hello w w w my dear get bang it is class 12s so solution in the chapter solution sir chapter solution okay so shall we get started Square can I see some excitement can I see some energy in the chat sir session session two and a half hours to three hours so I think three hours we we'll keep it at three hours okay and to be honest it's a very interesting chapter okay so let's get started without any delay so number 12th standard chemistry I'm keeping up my word second second so now let's get started we will continue to support okay and already you know this is going to be fire okay so first session exam so I will teach only what is there in nothing more nothing less okay I want you guys to have your NC with you okay I want to teach everything in this book The Chap 25 26 pages I want to cover so the session okay so great let's get started so I will try to reply okay great so we use lot of substances right we use many materials in our day-to-day lives right and pure substances majority of the time substances they are all mixtures they're not pure substances so mixt mixt we are going to study about homogeneous mixtures homogeneous mixtures their composition and properties are uniform throughout the mixture so so what do you mean by homogeneous mixture their composition is uniform throughout the mixture even their properties are uniform so density density throughout the mixture is the same so that is what I'm trying to help you understand homogenous mixt soltion we going to deal with homogeneous solution okay are you all clears problems discuss I will only teach you theory of the entire chapter the session will be on problem solving previous year board exam questions from this chapters okay pyqs and problem solve okay great so we use lot of substances in our day day-to-day life and most of them are mixtures they're not pure pure substance very rarely we use so mixt homogeneous mixture homog composition and properties are uniform throughout the mixture okay solution solution what whatever is present in largest amute okay are you all clear very good so a solution is a homogeneous mixture of two or more than two components dispersed on a molecular scale so solution it is a homogeneous mixture of what are we going to mix we're going to mix solvent and solute two or more than two you can have more than two components and number in the chapter two components okay so we are going to study binaries solution so binary solution now you have R component you have a solvent and a solute solute can solution you can have solution are you all clear so binary solvent solute solvent solute Sol I hope you understood solution so let's stick to that okay great so now moving on in solution the component which is present in excess amount is called solvent the component which is present in less amount is called solute okay great super a solvent when it is dissolving a solute it forms a solution simple solute solution suar solution super are you all able to follow so chap starting and the chapter Beautiful chapter you will enjoy it I'm telling you okay so let's go slowly andev osmotic pressure reverse osmosis and abnormal Mass I have so many good things to teach you okay in this chapter so now let's move forward okay always you can have a gous solution you can have a liquid solution you can have a solid solution can you believe that okay so the the state is given by the state of the solution is given by the solvent State G solution solvent full of gas liquid solution now solvent full of liquid solid solution now solvent full of solid this is very important so the physical state or the state of the solution is determined by your solvent so gaseous solution so there are nine categories there are nine categories okay so in the examples okay gas gas mixture of oxygen and nitrogen liquid gas chloroform in nitrogen solid gas Cur so campur in nitrogen gas gas in liquid oxygen in water which is which is important for fishes aquatic organisms for breathing right I hope all of you are aware sir in the chapter full of M amama Sur for sure I will finish this chapter today and I'm going to teach only the theory theory part of this chapter today problem solving problems previous years questions leure okay very good like I said oxygen dissolved in water gas obv gas in your liquid right so that is what is helping aquatic organisms to live liquid liquid ethanol in water example examples solid in liquid glucose in water Sakura in water like that gas in solid solution of hydrogen in padium then you have amalgam of mercury in sodium then you have copper dissolved in Gold so in the examples it's not very very very tough it's not very very tough you can remember it when you just keep writing it down keep noting it down are you all are you all ready shall we get started yes super super level Pang great so expressing concentration of solution solution the concentration of solution is very important it will change it will become different so I will tell a better way of better way of studying okay concentration one part per million million part one part per million 1.5 part per million out so that is why it's important to study concentration it is important to understand what is the concentration and the the terms injection conation terms are there so as a science student you need to understand what they mean so I'm going to teach you all that is given over here okay so we have mass percentage which is weight of solute by weight of solution okay weight mass mass of solute by mass of solution volume percentage mass by volume percentage parts per million I'm assuming both of them you guys are very well aware of some basic concepts of chemistry which of them depends on temperature which of them does not depend on temperature can you please let me know temperature dependent temperature dependent can you all please let me know answer what is the answer Guys these are all very good questions very good marity marity depends on temperature Mass dependent so this will not change with temperature so temperature does not affect your mity so mity temperature independent temperature dependent so first percentage now mass of the component in the solution solute solvent divided by total mass so mass of solute by total mass of solution will give you mass percentage of solute mass percentage of solvent K mass of solvent by total mass of solution into 100 okay are you all clear very good so my solution is 10% 10% glucose in water solution 10% glucose in water and 10 G so 10 G of glucose in 100 G solution 100 G solution glucose 10 G water glucose of glucose 10% glucose in water solution sir 10 G glucose 100 gram water sir 10 glucose 100 water 10% glucose so this is a mistake which people make so 10 G glucose in 100 G of solution so 100 G solution solution you have both solvent and solute solution you have both solvent and solute okay so 10% glucose now 10 by 100 is the percentage 10 by 100 now mass percentage so that is mass of glucose by mass of solution so solution Mass 100 glucose Mass so solvent sir mass of solution mass of solvent plus mass of solute so 100 of solution mass of solvent sir mass of solvent 100 minus 10 sir 0 g I hope all of you are able to understand so shall I move forward let's go forward to the next one which need students which students should know exam Mains for example commercial bleaching solution contains 3.62 percentage mass percentage of sodium hypochloride in water okay how many of you have marked it in NC how many of you have spotted this okay so 3.62% of sodium hypochloride right so sodium hypor solute ande percentage volume percentage Now volume of the component by volume of the solution volume percentage volume of the component comp volume percentage of solute then the formula is volume of solute by volume of solution into 100 so 10% ethanol solution 10% ethanol solution that means 10 mL of ethanol is present in 100 ml of water or solution not water solution I'm sorry okay so if let's say you have 10% ethanol solution okay 10 10% ethanol solution now you have 10 mL of ethanol in 100 ml of solution in 100 ml of solution so 10% ethanol solution volume by volume are you all clear so shall I move forward very good super super Pap let me see if you guys are able to answer okay very good ratna W ratna nice to have you here Welcome to our Channel ritwik yes RK I will do that please wait yes yes please go through it what is the what is the important thing very good Anisha ethylene glycol ethylene glycol is a antifreeze which is used for cooling so e g it's an antifreeze so it will reduce the freezing point even below zero Masa so number number freezing point of water it reduces to- 7 .6 correct it reduces to- 17.6 so water can be chill water can be very very cold and still not freeze at zero so which is good for cooling so that is what we use and that's why the name antifreeze important so what is antifreeze it is a 35% volume by volume solution it is a 35% volume by volume solution of ethylene glycol I hope all of you are clear okay fantastic so now let's move forward mass by volume so mass of solute by volume of solution into 100 okay of solute in 100 ml of the solution GRS of solute in 100 gram of your in 100 ml of your solution okay so how many grams of solute is present in 100 ml in a volume 100 ml of my solution mass by volume percentage it is used where mass by volume where is it very commonly used in medical field Pharmacy very good Tom Jerry V level Tom Jerry V level so it is used in pharmacy medical Fields that's awesome okay so now let's move forward parts per million Pang this is very important so where is this used very commonly this is used very commonly for pollutants atmospheric pollutants water pollutants so pollutants major they use parts per million when you have very little traces of solute in a very very large quantity of solvent so parts per million use part when you have traces of solute solute in very very large quantity of solvent so we use parts per million so parts per million formula number of parts of the solute number of parts of solute divided by total number of parts of the entire solution into 10^ 6 into 10^ 6 parts per million okay so formula and a lit of sea water weighs 1030 G in contains this much amount of dissolved oxygen so solute solute so weight of solute number of parts of solute in the parts per million it can be mass by mass it can be mass by volume or it can be volume by volume the PPM number of okay you can use mass by mass or you can use mass by volume or you can use volume by volume given of solute and they have given you mass of the solution you know sea water the solvent and solution so30 G so I'll get 5.8 by 10 6 don't you all agree if you divide 6 by 1.03 you will get 5.8 in the 10 power minus 3 Kil it will become 10^ 6 you can check it so 6 ided by 1.03 into 10 ^ 3 into 10 ^ minus 3 so that will become what 5.8 divided 10 6 so 5.8 G per 10 6 G okay so we can write it as 5.8 PPM 5. so 5.8 PPM it is 5.8 G in 10 to the 6 G of solution so 10 the^ 6 G of solution 5.8 GP are you all clear so shall I move forward everybody cool with this so I hope all of you are able to follow mole fraction Frac a number of moles let's say n a b number of moles NB so Mo fraction of a number of moles of a by total number of moles mole fraction of B it is number of moles of B by total number of moles so mole fraction definition mole fraction divided by total number of moles okay very good so it is nothing but number of moles divided by total number of moles all components let say comp fraction fraction of a fraction of B should give you one are you all happy are you all here everybody sir marity depends on temperature please wait okay so now let's move forward my dear boys and girls very good so for a binary for a binary solution for a binary solution the two components or mole fraction add I will get one so the two component binary solution compute one very good so fraction formula for fraction so please be ready okay so please be ready we are going to use this in many places today so let's go forward like I said so I will cover everything it's going to be super interesting so please stay till the end and listen to whatever I have brought for you today okay great so mole fraction of ethylene glycol in a solution containing 20% of ethylene glycol by mass okay soang let's say solution weighs 100 gam okay so solution let's take solution so ethylene glycol so C2 h62 ethylene glycol how much it is it is going to be 20% of our solution 20% of 100 gram is 20 gram okay so remaining is what remaining is going to be solvent water so water is remaining so 100 total solution solute e gcol okay I hope all of you are able to follow that so moles of eth gly moles of eth gly mass by mass by molecular mass so mass of Ethylene glycol is 20 G by m Mass calculate C2 24 H6 30 O2 uh 32 so 62 so 20 by 62 number moles of ethylene glycol and moles of water moles of water is weight by molecular weight so both of them you can calculate now mole fraction mole fraction of ethylene glycol is moles of ethylene glycol by moles of ethylene glycol plus moles of water so that is your answer can you guys please finish it off answer are you all clear okay are you all happy with this my dear boys and girls super ready calculation guys I don't want to do that you guys can do it see you have to get what 0.322 ethine 4.44 mes the answer is uh 0.68 okay so okay 0.068 0.068 the answer 0.068 you guys are absolutely correct okay so solution only two components it's a binary solution so binary solution fraction 0.068 water fraction one minus mole fraction of ethylene glycol so it's one minus 0.068 that is going to be uh you can find out no 0.932 if I'm not wrong right so it's 0.932 that is the mole fraction of water so that's the definition right I hope all of you are clear super so it's a very but it's good for revising fraction I wanted to revise solution you can go through it now now I'm going to talk about marity marity depends on temperature so please it depends on temperature volume volume volume is a temperature dependent quantity so temperature dependent quity it is dependent on temperature marity form moles of solute by volume of solution in liters okay moles of solute by volume of solution in lit so25 Mo per lit solution of Na you have 0.25 moles of NaOH in 1 lit of water of the solution okay in one liter of the solution P are you all able to understand I hope all of you are able to get the Ang of it per so per you can write it as m capital M so small M mity Small m mity capity so25 M solution .25 M25 capital m capital M marity which is temperature dependent okay I hope all of you are clear so it is 0.25 M now25 moles of NaOH in one liter of solution okayy part this is mity mity on the small M mity on the small M okay I hope all of you are able to follow everybody clear so mity is temperature independent so temperature so is what moles of solute by mass of solvent in prop cative properties elevation in boiling point depression in freezing point okay so mity moles of solute by mass of solvent in kg okay so one Mo per kg that is nothing but one m one m Solution One M solution Mo of solute is present in 1 kg of solvent okay I hope all of you are able to understand so one small M solution of KCl now Mo of KCl is present in 1 kg of water solvent denominator it is mass of solvent not Solution please be clear please don't do it wrong so m is the solution concentration in mity harini mole is the amount of substance so mole is very different mity is a concentration term so they both are very different okay great so sir does one lit weigh 1 kg sir no sud who said that that's only for water so water M it depends on temperature and pressure all that matters so water generally one one one lit weighs 1 kg okay have you guys seen that so okay great so continue are you all ready so shall we move forward it was good right super okay so we'll continue what is solubility see solubility you have to dissolve something in something okay so dissolve a solute in a solvent so that is what is solubility define solubility okay so what is solubility it is the maximum amount of substance that can be disolve in a specific amount of solvent okay so solubility so for example what is the solubility of stand what is that called that is called saturated solution very good saturated solution so okay and this solubility depends on temperature and pressure so you have to do this at a specific temperature temperature pressure we do it at a specific temperature and pressure only then we can get the correct solubility I hope all of you are able to understand so solubility what is the maximum amount of solute that you can dissolve in a specific amount of solvent in a specific temperature solity of a solid in a liquid okay solubility of a solid in a liquid you should understand every solute will not dissolve in every solvent you should first understand that every solvent cannot dissolve every solute so we need to understand the chemistry behind this okay great so we have solvent as liquid and solute maybe a gas solute maybe a solid solute maybe a liquid so solute we are going to keep as liquid okay so solvent liquid so liquid solvent solubility when we have solid when we have liquid when we have gas as a solute in Aid in a liquid solvent water solvent liquid so water is an example okay water water is an example of a solvent of what I'm going to talk right now okay so dissolve it wony in benzene you have you have anine so you have napoline anine they they can dissolve in Benzene so napoline is a solute Benz Benzene is a solvent so Benz anine salt and sugar naine and anine will they dissolve in water no so polar solute will dissolve in polar solvent nonpolar solute will will dissolving non-polar solvent so like dissolves like I hope all of you are able to understand that okay are you all clear so shall I move forward dissolves po solvents dissolve polar solute nonpolar solvents dissolve nonpolar solute so Benzene solvent naine and anine will dissolve because dissolves because polar solvent polar solute light dissolves like I hope all of you are able to follow now let's move forward there should be a slight difference in your polarity like uh you have slightly negative and slightly positive so water number hydrogen is slightly positive and oxygen is slightly negative because electro negativity of oxygen is very high so it will attract the the shared pair of electrons towards itself so oxygen will be slightly negative and hydrogen will be slightly positive so polarity po molecu I hope you are all aware of it maybe I'll take another class not right now okay so solubility of solid in a liquid Gua I want to teach you a lot of cool things so please listen carefully so solution disv disolution so there will be two kind of things which are happening two processes one is disolving another is crystallization so solute you are continuously doing it so it happen it'll be happening continually so you will have equilibrium you will reach saturation I hope all of you are able to understand I hope all of you are able to understand are you all clear everybody body happy so when you when youif Sak Sak in your you are having two things happening which you don't realize so it will be in equilibrium at saturation and that is why it is called d dynamic equilibrium that is why it is called dynamic equilibrium equilibrium is dynamic what do you mean by dynamic dynamic the forward and backward reaction will be of equal speed forward back rate of reaction will be equal so reaction for example disar become solid become solute it is constantly happening your forward and backward reactions are going to be equal but when you see it from outside it'll be as though nothing is happening so equilibrium so state that is what you call a saturation point so that is what you call as a saturated solution saturated solution it will be undissolved are you all clear everybody happy I hope all of you are able to understand so initi wait I'll explain it to you dissolving so initial forward reaction is more because you are dissolving dissolve at one point the backward reaction also will increase in speed so at one stage they both will become equal that is what you call as equilibrium saturation point you will reach equilibrium I hope all of you are able to understand is that clear I want everybody to please let me know in the chat you will get full mark in your board exam are you all happy with this everybody clear no doubts whatsoever great so can the equilibrium chapter you would have studied le le CH principle so I am going to teach that also right now okay so solute it is in equilibrium with the solution it is called saturated solution so saturated solution you cannot dissolve the solvent dissolve the solute you cannot dissolve the solute beyond the saturation point it will be undissolved okay are you all clear very good so saturated solution the the amount of the concentration of the solute which is dissolved is going to be your solubility so solubility the solubility is a maximum concentration of your solute which is dissolved in your solution at Satur saturation Point okay very good okay I hope all of you are clear so saturated solution solute maximum solution solute is maximum are you all clear so shall I move forward I hope all of you are happy with this okay so is your effect of temperature and pressure so temperature and pressure effect I hope I have covered everything I want to cover each and every topic so I hope I covered everything please let me know I will I will teach you okay super so non solute dep it depends on temperature and pressure also so what are the things that it depends on so solubility of the solute and solvent nature of the solute and solvent so nature of solute and solvent polar nonpolar nature of solute and solvent so is one of the factors factors temperature and pressure so temp you need principle okay so if if you're dissolving if it is endothermic endothermic reaction now then what will happen the solubility will increase with temperature endothermic you supply energy Delta endothermic you supply energy you are giving energy so endm Delta chemistry Delta is positive or negative Delta is what very good Delta positive or negative guys come on very good get Delta H is more than zero negative if it is endm okay endothermic now your Delta H is positive now increase in temperature will increase your solubility if it is exothermic then Delta H is negative then increase in temperature will decrease the solubility Masa so it leas principle okay so Lee CH principle says if your reaction is endothermic and if you are supplying more heat if you're increasing the temperature your solubility is going to increase okay are you are you all happy very good super great great great I'm so glad all of you have understood it now let's move forward let's go to the the part what is the what is the dependency on what is the dependency on pressure can anybody tell me what is the dependency on pressure please let me know see solids and liquids are incompressible so pressure has no effect okay pressure so solubility of a solid in liquid pressure has no effect because solids and liquids in general are incompressible unlike gases this topic is over I hope you all enjoyed it so shall we all go forward exothermic exothermic release of energy release of heat that is called exothermic endothermic it requires heat that is endothermic okay so I'm so happy that we are going at a good Pace we will complete it next topic is solubility of a gas in a liquid so I'm going to teach you the solubility in liquid solity you can have three possibilities solute gas you this okay I want you to know you should understand it way okay great so let's let's go forward Pang so solubility of a gas in a liquid so of a gas in a liquid that's because of dissolving of gases in your liquid so solubility of gas in liquid inting many life forms okay the solubility of Hy hydrogen chloride gas is very much in in water so water gas information please note it down okay very good SO gas solubility increase pressure should be more that's it if your pressure is more your solubility of gas is more that's it as simple as that okay so who gave the law what is that law and the law shall we move forward very good so let's let's get started and gasb will it is always in dynamic equilibrium so equilibrium gas will go into the liquid liquid will again come to gas so that that will keep happening so gas solute it come out so and the equilibrium will always be there so St okay I hope all of you are clear I hope there's no doubt about itas [Music] it to dissolve I hope all of you are able to get it yeah so diss and it will become equilibrium again it will reach a new point of equilibrium again are you all able to understand so diss the system will again readjust and reach a equilibrium stage again once again put in are you all are you all able to follow I hope all of you are able to understand whatever I've shared solil of gas in a Henry so Henry's law is very important to study the solubility of a gas in a liquid okay great very good very good super so now we are going to look at what is called as Henry's law so Henry's law it concluded independently that the solubility of a gas in a liquid depends upon the partial pressure of the gas soang partial pressure of the gasil are you able to understand partial pressure partial pressure of the gas gas pressure gas molecules pressure so partial pressure of gas it will go dissolve easily in the solent I hope all of you are able to understand so that is what Henry's law states it states that press so partial pressure is proportional directly to the solity also said that the solubility is a function of partial pressure of your gas the solubility is a function of your partial pressure of the gas I hope all of you are able to follow is that clear so what do you say what do you say in terms of mole fraction what is Henry's law Henry's law fraction mole fraction formula the partial pressure of the gas in Vapor phas the gas molecules it is directly proportional to the mole fraction of the gas inside the solution so what do you write this what do you write this as your partial pressure of the gas in Vapor phas Vapor phas Now liquid surface is proportional to the mole fraction of the gas dissolved mole fraction of the gas dissolved in the solution P are you all clear so proportionality constant now KH what is KH KH is called as Henry's law constant KH is called as Henry's law constant SOC I hope all of you are clear with this great great great very good superb so fraction of the gas in the solution gas term so it talks about experiment he has written it in a very formal form I hope all of you arear fantastic so now we'll move forward soas G that is a very very stupid answer okay so your partial pressure this hope all of you are able to understand did you all like it are you all happy so shall I move forward yes L okay so shall we move forward my dear boys and girls please let me know in the chat tap t very good super so let's move forward pangla that's about it I guess so soang what is the dependency on KH so K Henry's law con it depends on the it depends on what what can anybody tell me so partial partial pressure mole fraction they are directly proportional okay sir what does depend on Henry constant depends on what it depends on the it depends on the nature of what nature of your nature of your what great great so it depends on temperature very good very good so it depends on temperature equal p by Mo fraction okay so Henry constant fraction because they inversely proportional so Henry's law constant solubility come they are inversely proportional okay are you all able to understand yes very good so I will show you some values let's look at some values so Henry's law constant for various various solvents is given there okay for some various solutes is given there I'm sorry various solutes it's given there so you can check it for oxygen at 293 Kelvin so O2 293 kin left the KH value is 34.8 and2 gas gas it is solute is solute this is what is dissolving so 10° more K 46.82 so what can you infer from here what can you infer from here you can tell temperature Henry constant gas es they try to escape out so solubility will decrease gas will Escape gas will escape I hope all of you are able to understand so when you increase temperature what happens solubility decreases why your KH your Henry's law constant increases very good exactly it will remain soluble the gases will be inside inside the liquid and that's what you want right you want it to be gassy that that is what gives you good feel when you drink I hope all of you are able to understand so aquatic animals they prefer colder areas dissolved oxygen will reduce dissolv oxy aqu so Aquatic Life they prefer cold areas now do you understand that very good superb so these are the different values of K so K value it depends on the solute so depending on various gas depending on VAR solute your value keeps changing solubility is going to be coming helium solubility is going to be coming do you all understand that are you all able to understand my dear boys and girls everybody so helium or solubility com I hope all of you are able to understand so solubility in the K value it is it is depending on nature of solute and solvent it depends on that in the values for selected gas in water so KH value depends on your solute it also depends on your solvent so KH depends on nature of solute and solvent also on temperature okay so I hope all of you are able to follow solubility and helium solubility R I hope all of you are able to get it so that's it now let's move forward I hope all of you are able to understand any doubts please feel free to ask great so temperature same temperature then why changes temp nute gas depends on nature of solvent nature of solute and also on temperature so please be careful okay of tempure solity gas gas in a liquid okay so shall I move forward very good so the solubility of a gas decreases with increase in temperature this is because of Le chatus principle principle gas gas became water condensation gas will give out heat energy it will release heat energy and it will become liquid so when a gas dissolves and goes to liquid phase it will release energy so it is a exothermic process so solubility of a gas in a liquid generally is going to be exothermic exothermic now if you increase temperature the solubility will decrease because according to leas principle exothermic reaction temperature increase did you all like it are you happy did you all love it my dear boys and girls fantastic so shall we move forward great so let's go forward so we will have a look at the applications of our Henry's law so Henry's law various applications I hope all of you are ready energy are you all excited get batch where is the excitement where is it's a very important one so please listen carefully I will try to cover everything okay so applications of Henry's law so Henry soft drinks Coca-Cola Pepsi they are filled and sealed at high pressure okay they are sealed at high pressure yeah and high pressure your Coke your Pepsi everything comes sealed at high pressure SC water pressure is very high soing if you go to slightly deep water let's say 6 feet 8T expence and that's why water is so scary water is so scary because the water pressure is crazy it's very very high if you go swimming it will crush you submar the submarine submar the submarine which went to see Titanic exactly water pressure it made it small it compressed it pressure so SC pressure is very high okay gases will dissolve better correct gases gases will dissolve better so body all the gases will dissolve oxygen nitrogen disol pressure pressure gas gasas so it bubbles so nitren buels sometimes it is called bends it is called bends so bends are very very painful and sometimes times they can be fatal fatal so they will block our blood vessels nitrogen they also tell SC you have to come slowly so that the pressure difference is slowly raising got it I hope all of you are able to understand very good so bends they mix helium they mixi solubility value for helium is very high so helium solubility is very low so they mix oxygen with helium in the tank so that your parti pressure will be less it will beeded I hope all of you got it very good super so application application is mountains when you when you climb a mountain o press so then the oxygen that you need that will dissolve in your blood will also be less so your blood will have low levels of oxygen and because of this you might suffer from dizziness you might not be able to think correctly and that condition is called as anoxia okay super Lev so anox parti pressure so your blood dissolve oxygen level will reduce blood you have oxyhemoglobin oxygenated blood so your oxyhemoglobin your oxygen will start releasing outside partial pressure of o2 is less so your blood will contain less oxygen and because of that you'll have no proper thinking capacity and that condition you call it as anoxia okay very good so feel motivated and confident to go forward and teach the remaining part in a beautiful manner I want everybody please to let me know in the chat quickly yes fantastic usra don't worry usra are you try to charge and come back okay very good very good thank you so much boys and girls which is your R's law R's law it is for liquid liquid solution so liquid as a solvent and liquid as solute so you have a binary solution which has both liquid liquid only so that is what we're going to talk about and I will cover some simple simple part which all of us can follow okay great so Anisha I want to complete the full chapter today so let's go I am super excited and super pumped up I want you guys to completely know this chapter in and out okay very good so w i want you all to follow this and understand it clearly Divya yes Divya I will try to go forward I will try to uh speeding up the class a little bit okay so the pressure exerted by Vapor molecules above the liquid surface in in equilibrium with the liquid at a given temperature is called vapor pressure soap and you have liquid soap they will be so they will reach equilibrium at a specific temperature okay you will have this equilibrium established okay so EST the pressure which the vapor applies on the liquid surface that is called vapor pressure very simple okay now you'll be able to understand this much better okay I hope all of you are able to understand so the pressure which the vapor face the Vaper molecules above the liquid surface in equilibrium with the liquid apply is called as Vaper pressure okay superb so what are the factors which will affect vapor pressure purity of the liquid so this is very obvious pure solvent VAP pressure highest do you all agree pure solent pressure highest I hope all of you are able to understand okay so pure liquid is going to have higher vapor pressure than its solution okay I hope all of you are able to understand so number mix later on we will study we will study we will study positive deviation negative devision so pure liquid is going to have higher vapor pressure nature of the liquid so intermolecular we have weak intermolecular forces they are more volatile weak intermolecular forces more volatile more volatile moreap pressure so liquids which have weak intermolecular force of attraction so intermolecular force they are volatile volatile now they have a tendency to go to Vapor phase okay so then the vapor pressure will be higher did you all understand so that is why nature of liquid is also important lastly temperature the vapor pressure increases with temperature obvious Vapor molecules will increase and that's why your vapor pressure will also increase I hope all of you are able to understand simple so factors affecting your vapor pressure in the moon factors please now I'm going to go forward okay so liquid liquid I want to talk about non nonvolatile solute in a liquid okay so I hope all of you are with me great when you have a non volatile solute added to a liquid solvent okay when you have a nonvolatile solute added to a liquid volatile solvent okay so non volatile solute it is represented as that green color balls in your NC okay so pure pent which is a volatile solvent Escape I hope all of you are able to understand solvent we have a pure volatile solvent volatile G pure solvent so pure solvent which is volti top surface of the liquid your molecules will be there which can which can go to Vapor phase and Vapor phase will also come to your liquid phas and they both will be intile top surface non so there is less room for the for the volatile solvent to escape to Vapor phas so the vapor pressure will reduce how many of you are able to follow did you all love it this is what they explain for one two pages okay so pure solvent the top surface of the liquid there is lesser room for the volatile solvent to escape and go to the vapor phase so that is why the vapor pressure reduces so when you add a nonvolatile Sol solute the vapor pressure will reduce so pure solvent will always have higher vapor pressure than its solution pure solvent will have a higher vapor pressure than its solution when you add a nonvolatile solute okay great so let me read this quickly I hope all of you got it in such solution the surface has both solute and solvent molecules thereby a fraction of surface only is covered by the solent molecules and the fraction of the surface only is covered by solent molecules there is lesser room to escape consequently the number of solvent molecules the number of solvent molecules escaping will be reduced thus vapor pressure is reduced I hope you enjoyed it Dabba concept daba concept Masa so this decrease in vapor pressure is directly proportional to the quantity of solute present in the solution irrespective of its natureap pressure will reduce further so so the vapor pressure the amount by which it reduces depends on depends on the amount of solute present it does not depend on the nature of solute number of okay so so we have for this case what is this case this is when you dissolve when you are having uh nonvolatile solute in a volatile liquid in a volatile solvent so up there is something called as RS law for solution containing a nonvolatile solute so under RS law at a given temperature the vapor pressure of a solution containing non volatile solute is directly proportional to the mole fraction of the solt okay it is directly proportional to the mole fraction of theaction fraction ofv I hope all of you are able to understand okay are you all clear very good so yeah that's it pangla so the vapor pressure of the solution is equal to mole fraction of the solvent into this is what this is vapor pressure of the pure solvent this is vapor pressure of the pure solvent so I hope all of you are able to understand that okay solute it does not contribute toap pressure our solute is non volatile nonvolatile now it will not go to gas it will not go to your Vapor okay so solute will not contribute to your vapor pressure it is only by your solvent so vapor pressure of the solution is mole fraction of solution into what is this the pure solvent vapor pressure very good so pangla if so this is how this is how your vapor pressure will increase so mole fraction of solvent press because vapor pressure of solution is directly proportional to your M fraction of solvent so vapor pressure of your solution is directly proportional to your mole fraction of solvent so mole fraction of solvent press and maximum it is one when you have when you have pure solvent mole fraction one it is pure solvent that is no solute it is pure solvent so pure pressure maximum so when you have a pure solvent that is when your vapor pressure is maximum when you have something else let's say a nonvolatile solute that time your nonvolatile solute will also have some mole fraction so your vapor pressure will be lesser than the maximum value all know okay are you all clear did you all like it let's move forward now let's go forward so when you have two liquids shall we start I hope you guys are ready so if you're all ready friends so that they will also watch it and they'll also find it very useful and they'll grow okay so now when you have when you have a solution of two volatile liquids okay we have two volatile liquids so okay so it states that for a solution of two volid now solute to volatile liquid solvent to volatile liquid so gas so the VAP pressure of the solution is contributed by both of them I hope you understood okay so for a solution of two volatile liquids the vapor pressure of the liquid the vapor pressure of each liquid in the solution is less than the respective vapor pressure of pure liquids the vapor pressure of each liquid will obviously be lesser than the vapor pressure of pure liquid okay and the equilibrium partial pressure the equilibrium partial vapor pressure of the liquid is directly proportional to its mole fraction the partial vapor pressure is prop to fraction Henry for liquids how many of you are able to realize that basically partial pressure of the gas is proportional to mole fraction of the gas dissolved in in the solution pressure the vapor pressure of your liquid is proportional to its mole fraction here your partial vapor pressure is proportional to your Mo fraction soid okay soquid let's call it a and b let's call it a and b so pressure of a is equal to is proportional to the mole fraction of a and partial pressure of B is proportional to your mole fraction of B do you agree yes sir the vapor pressure of a will have this relation the vapor pressure because of B we'll have this relation and according to R's law the partial vapor pressure of a is proportional to mole fraction of a the partial vapor pressure of B is proportional to the mole fraction of B and what is the proportionality constant the proportionality constant is there pure solvent vapor pressure is there pure solvent vapor pressure so pure solvent vapor pressure now the vapor pressure pure solvent vapor pressure now the vapor pressure when you have only the pure solvent that is the maximum vapor pressure of that liquid that is the maximum vapor pressure for that liquid when you have the pure solvent so that is only p a KN okay I hope all of you are able to get it so what is the total vapor pressure of the solution the total vapor pressure of the solution now I hope all of you are aware of that so the total pressure the solution so what is the total pressure the total VAP pressure is nothing but your pure vapor pressure of a plus k b into pure vapor pressure of B so now we know that Kai a plus k b that is mole fraction of a plus mole fraction of B is equal to one so using that you can simplify it you can write it in just in terms of one mole fraction amazing did you love it it's over it's done amazing right such a easy concept I hope all of you enjoyed it I hope all of you are able to follow so let's go forward like I said for a solution containing two liquids a and b r volatile RTI pressure contribute so the partial vapor pressure of a according to R's law according to the partial VAP pressure of a is proportional to mole fraction of a and similar the partial vapor pressure of B is proportional to the mole fraction of B and what is the proportionality constant the proportionality constant is nothing but your pure solvent vapor pressure okay so that is a maximum vapor pressure for that solvent for that liquid okay are you all clear everybody happy very good so pangla according to the partial VAP pressure of a is proportional to mole fraction of a so proportionality remove we will get equality equality you have proportionality constant so you need to find this so I will make mole fraction of a as one mole fraction of a as one k is equal to the partial pure solvent it is a pure solvent pressure it will be pure solvent vapor pressure so shall we move forward shall we go ahead yes so you can remember it like this also you you will not forget ever so you will get get the total vapor pressure of the liquid of the solution okay so you will get the total VAP pressure of the solution par graph okay are you all clear I will try to help you in the pressure of the solution total vapor pressure of the solution you get it by adding PA a plus PB okay and XA plus XB is equal to one so x a plus XB equal to one now if you want to write it in terms of XB xB is equal to 1 - XA that is nothing but your Kai that is nothing but your Kai okay Kai is nothing but your mole fraction okay I'm just calling it X for your Simplicity okay don't get confused great soang now let's let's plug it let's plug it over here so what is k k is nothing but Kai a is nothing but 1 minus k b so 1 minus k b plus uh partial pressure partial vapor pressure of B which is your pure solvent VAP pressure of B into Mo fraction of B so simp sir you will get pure vapor pressure of a plus K pure vapor pressure of B minus pure vapor pressure of a so that is the relation now let me explain the graph okay let me explain the graph everybody please listen carefully do you all understand that I hope there is no problem in that I hope there is no problem in that I don't want anybody to have a problem over there yes shall I move forward come on guys what are you all doing very good super so I have expressed everything in terms of Mo fraction of B explain everything in terms of mole fraction of a mole fraction of a R easy so uh pure vapor pressure of a into K A Plus pure vapor pressure of B into k b k i can as 1 minus K so simp the total vapor pressure of the solution will be equal to Pure vapor pressure of a minus pure vapor pressure of B into k a plus pure vapor pressure of B that's it so in terms of K in terms of okay I will try to draw the graph one by one and then we will move forward Okay so so in the in the y axis that vapor pressure okay and X fraction fraction maximum and minimum so a press we will write the partial vapor pressure of a what is partial vapor pressure of a partial vapor pressure of a is the pure solvent vapor pressure of a into mole fraction of a so mole fraction one now that is the maximum that is going to be the pure solvent vapor pressure of a that is going to be pure solvent vapor pressure of a and when mole fraction is zero then the partial vapor pressure of a is also zero so because of a it will be like this Masa because of a it'll be like this Sama are you all clear are you all able to understand this shall we move forward my dear boys and girls are you all happy great so let's do it for B so partial vapor pressure of B is the pure solvent vapor pressure of B into the mole fraction of B so mole fraction of b z and mo fraction of B it rises as I move to the right it becomes one here so FR so the partial vapor pressure of B let me see when mole fraction of B is one when mole fraction of B is one the maximum the maximum which will be what which will be your pure solvent vapor pressure of B and when mole fraction of B is zero that will be minimum that is when your partial vapor pressure of B is minimum so partial vapor pressure of B is minimum and it raises to the maximum value so so partial VAP pressure parap pressure are you all able to understand I want the total vapor pressure so total vapor pressure is what addition of both of them so the graph will be like this m so on the complicated graph duac chipo did you enjoy it are you all happy my dear boys and girls s very good super P I'm glad you all enjoyed it so that is what is drawn over here are you all clear very good so let's go forward we are done with our RS law I I hope all of you are checking we have we have completed literally everything okay I happy so almost okay why pa maximum value is less than PB it depends on and so let's say in the more volatile so we have two volatile liquids left so in the gra B more volatile pure solvent vapor pressure is higher so pure solvent VAP pressure higher other more volatile so more volatile one will have a higher value and less volatile one will have a lesser value I just do it simply tum I took whatever is given here but what you can infer is a P soless more volatile got it yes yes Nan you are right more PB not okay great so now we'll come to the deviations so let's come to deviations this is very important and I will cover a lot of good things here okay so pangla I hope all of you are ready no I I I guess the energy is still there are you all tired are you all bored okay okay let's continue okay so now what I'm going to teach you is uh what are ideal Solutions and what are non- ideal Solutions okay I'm to teach and I I really found this chapter to be very interesting honestly this is actually a super interesting chapter okay and this part this part you will enjoy a lot okay so very good so let's continue so what are ideal Solutions ideal solution they should follow your RS law R follow ideal solution and that means it follows non ideal it will not follow R's law it will deviate deviate we will try to understand okay soang ideal solution Solutions are those Solutions which obey R's law over the entire range of concentration okay so whatever solution obeys R's law or the entire range of concentration are called as ideal Solutions so in that means follows law if it follows R's law it's called ideal solution soide solution 20 minutes is going to be super awesome I will guarantee you that 20 minutes is going to be super awesome listen carefully so suppose in the IDE solution I dissolving a in bve to get a solution the solution when when you have we have the same kind of the same kind of Attraction same kind of attraction between all the possible pairs so tyes a molec b molecules so when I dissolve it you are going to have AB molecule interaction also solution so exact IDE solution IDE Solutions so IDE solution when your a interaction BB interaction and and this is also similar you might have a ideal solution so ideal solution properties the Delta V of mixing solvent the change in volume is zero after and before mixing so there is no change in volume for ideal Solutions Delta H mixing is also zero Delta H mixing is also zero the bond mixing is also going to be zero so examples of this is what ncrt textbook hexan heptin so these two are going to form near ideal solution Benzene and toin Benzene and tolin hexane and hepe chloro chloro ethane and bromo ethane that is also example bromobenzene and chlorobenzene ethy bromide ethy chloride these are all examples of Ideal near ideal Solutions so exact ideal form it's very rare but these are all near ideal Solutions which follow R's law almost fully okay so ideal Sol please Sol attraction it should be similar almost it should be similar almost Delta mixing that is the enthalpy of mixing when you mix both the A and B A solute B solvent mixo that enthalpy is zero because their a interaction BB interaction AB interaction Moon force of attraction May similar and Delta V mixing is also zero so ideal solution characteristics I hope all of you noted this down so la follow under ideal solution should have these three characteristics and you should remember the examples are you clear shall I move forward the whole and the whole par I have completed this I hope all of you enjoyed it now let's move forward sir nonideal sir nonideal those Solutions which do not followw nonideal so your partial VAP pressure of a is not equal to this partial VAP pressure of B is not equal to this equal to it obeys R's law so first one now if they are not if they are not following R's law they can be of two types one is called positive deviation another is called negative deviation is so please listen carefully the solutions which do not oby are called non ideal Solutions now non ideal solution the force of attraction the force of attraction between between AA molecules and BB molecules are different from Ab molecules that is very very important so on a molecular level on a molecular LEL non ideal Solutions non ideal Solutions force of attraction between AA and BB will be different from your a molecules so it does not follow solution attraction BCE of Attraction will be similar to that of ab we have two kinds of deviation so we have two kind of I'm going to teach you so for nonideal solution the Delta V mixing is not zero the volume change after mixing is not zero and enthalpy change is also not zero Okay so so the VAP pressure of a solution soltion pressure solution compared tow did you all like it are you all happy so if the vapor pressure of the solution is higher than that of what we find using R's law then you have positive deviation if if the vapor pressure is lower than what you find with r's law then it is going to be negative deviation clear great SOI pressure but you see it is going up and solution pressure the the VAP pressure of the solution total did you all like it are you all clear everybody happy with this my dear boys and girls so positive deviation okay good great I hope you enjoyed it so positive deviation do you understand don't you agree so first point the magnitude of ab interaction Force as compared to AA and BB so liquid force of attraction between a and Masa so because AB interaction is weak they do not stay in the solution long they want to escape okay they want to escape and move out I hope all of you are able to understand are you all clear everybody happy Square fire and can you all guess can you all please guess why Delta V mix is positive and Del H mixes positive Delta V mix is positive final volume is more after you mix these two the final volume is more why can anybody guess why anybody please let me know quick quick quick quick okay I'll come to that because we mixing you understand know to remember this becausei deviation due to weak force of attraction soltion if they have good attraction they'll stay in the liquid phase interaction is weaker so interaction they do not want to stay in the solution phase solution for long they want to escape to vapor andap pressure I hope all of you are able to understand great so positive deviation examples acetone and water and acetone and carbon disulfide how many of you have seen that I will tell you the page number also page number page number 14 have you guys seen that everybody please go check it out page number 14 you will see the positive deviation mixtures of ethanol and acetone then you have uh acetone and carbon D suide okay so examples I hope all of you are able to recognize that so now can can anybody let me know ethanol and acetone now why will it form a positive deviation solution EOL acetone can anybody let me know so please think think think and let me know yeah I want you to invol I want you to respond in the chat be quick easily break the bond very good DMI super super super heying I want you to read you are having your NC book in your hand and still you're not saying this AB interaction will be weaker very good molecules are hydrogen bonded pure ethanol molecules are hydrogen bond the interactions are going to reduce okay acetone and carbon dulf so acetone and carbonide acone and carbon disulfate also you will have very similar interaction so in the positive Dev when your interactive forces when your force of attraction is weaker as compared to your AA interaction and BB interaction examples acone and carbon disulfide acetone water examples and now cause of positive deviation I'll explain okay so when cyll xan is added to ethanol cyc xan tries to adjust between alcohol molecules breaking the hydrogen bonds of host molecules this causes to weaken the intermolecular attraction between the alcohol molecules therefore the escaping tendency of molecules increases and vapor pressure increases simp acrogen bonds so molec hyrogen Bond so strong they have some bonding force of attraction so the tendency to escape will increase tendency to escape increases now the vapor pressure increases did you like it I hope now it's c crystal clear crystal clear I want everybody to let me know in the chat acetone and carbon disulfate negative deviation lesser Tanisha Tanisha please read I want everybody to read acone and carbon disulfate so acetone and carbon dare also will come in the same para under positive deviation so please go and check it Tanisha acetone and carbon dulf is also positive deviation okay so for such Solutions so for positive deviation Delta H Delta V positive so easy soy negative deviation negative so for ideal solution Delta H mixing Delta V mixing is zero for ideal solution Delta H mixing Delta V mixing is zero but for positive deviation positive deviation for non ideal solution positive deviation Delta H and Delta V both are positive yes sir as energy is required to break the hydrogen bonds so why Delta positive because for positive deviation you need to break the hren bonds soy you have to spend energy spending energ vular Force spre did you like it so of Attraction the molecules will move apart volume so that is why Delta V is positive so that is how you learn non ideal solution now let's move forward okay are you all clear my dear boys and girls shall we proceed so let's go forward to the negative Devi negative Devi negative deviation ab ab intermolecular attractions are more strong than AA and BB so solute a solvent B so solute a solvent B AB inter force of attraction is stronger so solution attraction stronger it can keep them in the solution and not let them Escape easily so pressure for negative deviation graph for negative division a partial VAP pressure according to R's law it is supposed to be a straight line in the blue line pressure according to R's law it is supposed to be this green line straight line but and total vapor pressure of the solution should be this red line so negative deviation the total weap pressure of the solution will reduce okay are you all clear we'll try to complete great I'm so happy this is such an important one so AB intermolecular force of attraction is stronger than a a and BB so negative deviation your total vapor pressure of the solution will reduce and negative deviation volume mix Delta V mix and Delta H mix both are negative so negative deviation everything negative and reduction in vapor pressure positive deviation everything positive Delta H positive Delta V positive and vapor pressure also increases okay great so are you all ready great great great Soo example of this is chloroform acetone and you also have phenol analine so are examples so what are the examples of solutions which show uh negative deviation chloroform and acetone positive deviation acetone e acetone carbon dul examples are very important acetone carbon disulfide acetone ethanol is positive deviation negative deviation chloroform acetone phenol and anine so a b so a hyrogen bond form so between phenol and anine you will have hydrogen bond formation so hydrogen bond formation between your phenol and your analine so you have a lone pair so you hydrogen bond formation okay are you all clear I hope all of you are able to understand day one second one second one second I'll start please wait please wait I'll clear all your doubts sir chemical kinetics physics elatic potential and capacitance chemistry chemtics chemicals I'll go to electrochemistry okay I hope all of you are clear so Bing you will have attraction so the intermolecular force of attraction increases so they will be held in the solution in the liquid pH great so this is what I wanted to share Pang so I hope you liked it so chloroform C chcl3 chloroform and acetone acetone is what your propanone your propanone and your chloroform chcl3 both of them have hydrogen bond so between a and b a b you are having intermolecular force of attraction hydrogen bonding because of that the attraction is strong they are held together in the liquid phase and that's why the vapor pressure is reducing okay so the escaping tendency will reduce they are held together so they cannot Escape easily P are you all clear so why Delta H is negative because hydrogen bond is formed if bond is formed then energy is released so bond is formed because of attractive forces so energy is released and energy is released it is exothermic it's going to be Delta H negative Delta is negative means energy is given out Delta V negative Now volume is reduced why volume is reduced because attraction attraction the molecules are coming closer if molecules are coming closer the volume is going to reduce it's going to shrink that's why Delta V is negative m Tropic [Applause] mixtures okay I will make it super easy for you please listen carefully okay I want everybody to listen carefully this is super important so aop let me go to distillation they separated out they separated out by fractional dis fraction you will have you have water you have other things boiling for example let's 78° and water 100° okay 78 4 I think e is 78.4 fractional distillation are you all clear aop aop they are mixtures of two different liquids mixture which boil at the same temperature R different liquid mix they will have the same temperature of boiling soop mixture aotr mixture P both both will boil at 78.1 so androp mixture the mixture will boil at 78.1 so aot Tropic mixture in they have a constant boiling temperature for both the liquids and it is hard to separate both of them by distillation M so aotrs they are mixtures of two different liquids which boil at the same constant temperature and distill with unchanged composition okay I hope you liked it so these are formed by non ideal Solutions so you in the aot Tropic mixture form only non ideal solutions that is whichever does not obey your RS law so minimum boiling boiling point boiling point shim 78.4 water boiling 100 aop mixture aot Tropic mixture will boil at 78.1 sir the isotopic mixture of ethanol and water is boiling at a temperature lower lower than both of them then it's called minimum boiling aot tropes Masa did you love it what is it good level so the isotopic mixtures which have boiling point lower than either of the lower than either of the components are called as minimum boiling aot types aotop and they are formed by they are formed by liquid pairs which show positive deviation so non ideal Solutions which show positive deviation they only can do this they they only can form this minimum boiling a tropes okay and maximil it's understood so maximum boiling a aotop the constant the common boiling point the constant temperature at which the mixture boils will be higher temperature than either of the components than either of the components and that is what we call as maximum boiling aot tropes and they are usually formed by those liquid pairs which show negative deviation from ideal Behavior that's it I hope you enjoyed it so bang ctive properties so this I will probably continue in another session tomorrow and we will solve some questions also okay so and I hope it was useful I have tried to cover every single thing in ncrt if I did not please let me know I will help you out okay so did you all enjoy this so that they'll also be a part of our sessions and they'll also enjoy okay are you all happy yes so we have still four more topics we have we have abnormal masses your vanoff Factor so I will try to complete it so now I'll continue tomorrow but like I said I will need your love your participation and your involvement important I hope you will continue to do that okay okay thank you so much love you all take care and all the best guys byebye