hi welcome back my name is andrew pardo today we're doing lab number seven and it's the ionization and classification of acids salt bases and salts and classification of electrolytes pretty much so what is another we have in a solution you have three classifications of electrolytes you have uh something known as a strong electrolyte we're going to abbreviate it as s e then you have a weak electrolyte abbreviated as w e and then we have a non-electrolyte e so in a strong electrolyte what we're seeing is that we have 100 disassociation such as we'll say a great example would be hcl when hcl is dissolved into water we see we have formation of the proton and the chloride ion so this is all going to the product side meaning we have 100 disassociation where we have the chloride ion and the watt and the proton ion being formed in the water now for a weak electrolyte we're saying we're going to use acetic acid and that is ch3 c o o h since it's a weak electrolyte it's actually an equilibrium from going from a molecule side and in the on the right hand side of the chemical equation we have protons being generated and on top of the proton we have the acetate ion being formed but it's about it's a balance between ionic ions in solution and molecules in solution since it's going back and forth therefore we have what we call the weak electrolyte and then last but not least our non-electrolyte such as methanol ch3 oh we know methanol is a polar molecule it dissolves nicely in water however when you dissolve it in water ch3oh it stays intact so all you have is aqueous methanol we agree we indicate it by using the this subscript or this small casing showing aq meaning methanol in water so that's what we're going to be identifying here if it's a strong electrolyte we should be able to see uh the light bulb shine very brightly if it's a weak electrolyte the light bulb is going to be very dull if it's a non-electrolyte the light bulb's not going to shine at all so that's what we need to identify here in this lab before we start the lab make sure that we have proper protective equipment on which is our nitrider gloves and our safety goggles we're dealing with high concentrated uh we have some high concentrations here and therefore we definitely need our protective equipment so the setup for this is different solutions at the specific concentrations we're going to be then taking these solutions and putting them right here where we have these two open wires the light bulb's already plugged in the back so we have electricity but technically electricity isn't running through here until we put the solution we dip these two prongs into the solution so we're going to go ahead clean this out real quickly and we need to make sure to clean out these uh prongs after each uh test so first on the test is distilled water so distilled water means there is no ions in there so we can we can hypothesize that since there is no water in there i mean no ions in there technically this should not this should be an non-electrolyte do the light bulbs shine no therefore distilled water is none water itself is a non-electrolyte let's go ahead and remove it okay now we're going to compare it to tap water this is water taken directly from this tap right here we're gonna go ahead and put it so you can barely see here the filament that's inside the light bulb it's it's turning in the color pretty much it is lighting up so the tap water has some ions present in it as opposed to di water so if it's a weak electrolyte you should see something like this the filament barely changing color or barely lighting up okay just to make sure clean it up all right sucrose sucrose the chemical formula for sucrose is given here c12h22o11 there is no this is a completely molecular compound so when we put the solution of sucrose in to we stick the probes into the solution of sucrose we see that we have no light we're not completing the circuit at all since the circuit isn't being completed therefore no light no electricity running from one side of the probe from one side to the prong all the way to the other so therefore this sucrose is a non-electrolyte go ahead and rinse it out okay potassium chloride potassium chloride is a metal with a non-metal we know that this is an ionic solution the concentration of potassium chloride is 0.2 so we're going to put this solution we're going to stick the prong prongs into the potassium chloride solution and i got an idea it is a very bright light therefore this bright is since the light is very bright we know that potassium chloride solutions are strong electrolytes so this is how strong electrolytes behave the light bulb is very bright meaning potassium chloride ion underwent 100 disassociation potassium ions being formed as well as the chloride ions being formed in an aqueous solution rinse that off all right now concentrated acetic acid concentrated we call it concentrated acetic acid or when you buy it commercially it is known as glacial acetic acid glacial acetic acid or concentrated acidic acid means there's very little water in there it's 99 percent acetic acid we know that acetic acid is a weak acid so what do we expect to see there we go takes a little time so since it's concentrated means there's a lot more of the molecule present the acidic portion as opposed to the acetate and as opposed to the proton being formed so if we want to see some if we want to see this light bulb shine a little bit brighter we're going to go ahead and dilute it by diluting it we're definitely creating a lot more ions in there than we are uh then it does in the concentrated solution so now we're going to compare the concentrated acetic acid or glacial acetic acid to a 0.2 molar acetic acid and make sure that this is thoroughly rinsed there we go so because the acetic acid is dissolved into water and the concentration is 0.2 therefore that means we have a little bit more ions present than we do in the concentrated portion in the concentrated or glacial acetic acid yes it is a weak it is a weak electrolyte because compared to potassium chloride we're seeing that this light isn't as bright as it was for the potassium chloride now what ions are reforming here we are forming the acetate ions on the right hand side of the chemical equation and we are producing also the proton ions in the right hand side of the chemical equation so concentrated acetic acid is weak is a weaker electrolyte compared to a dilute form of acetic acid now hydrochloric acid hydrochloric acid is a strong acid if it's a strong acid therefore it should be a strong electrolyte let's see how that's true hydrochloric acid a very strong uh it's a very strong electrolyte this bruh this light is extremely bright okay so i'm using the word extremely but nonetheless it's a strong electrolyte compared to acetic acid this is a very strong electrolyte so what are the ions being formed there the proton ion and the chloride ion in aqueous solution ammonium hydroxide ammonium hydroxide is a a weak it's a weak base since it's a weak base therefore this should be a weak electrolyte and as we submerge it in the light is a dim it's not as bright as we saw with the hydrochloric acid so therefore ammonium hydroxide is a weak electrolyte ions being formed here are the ammonium ion and the hydroxide ion remember that this is a weak electrolyte now we're going to compare it to potassium hydroxide potassium hydroxide ionic uh compound dissolved in water it should create potassium ion and hydroxide ion so we should definitely have 100 disassociation because potassium hydroxide dissolves nicely in water and there it is it's a strong electrolyte very bright light bright light strong electrolyte so 100 disassociation there is no reversibility of this when it's a strong electrolyte now sodium nitrate sodium nitrate is a it's a salt it should also be 100 it is soluble in water it is a strong electrolyte very bright light it's a strong electrolyte the ions being formed here is the sodium ion and the nitrate anion next magnesium chloride it's a soluble salt magnesium chloride should undergo 100 disassociation this time i'm going to have three ions i have one magnesium two plus cation and the chloride anion two chloride and ions it is a strong electrolyte okay copper sulfate one of my favorite solutions because the copper sulfate solution is blue copper sulfate soluble in water light bulb is bright it is a strong electrolyte 100 disassociation so we have a copper ii cation and one sulfate anion being formed sure sunglasses sulfuric acid the concentration is pretty low 0.1 molar even though it's a low concentration we know sulfuric acid is a strong acid strong acid is a strong electrolyte meaning no reversibility 100 disassociation of the first proton now this one's a little tricky because you would think both of the protons would get disassociated no only one of these protons gets disassociated so this solution that we have here it has it's going to be sulfuric acid produces hydrogen sulfate minus one and one proton ion being disassociated okay go ahead and rinse this off last one methanol so methanol in water the concentration is 0.1 molar just like i showed in the example earlier methanol is when it dissolves in water it produces no ions since no ions are being generated this is a non-electrolyte so methanol not an electrolyte it's a soluble soluble molecular compound soluble water molecular compound okay so that's the first part of the experiment the second part of the experiment we will be identifying phs of solutions by using ph strips unfortunately i have this already here the solutions are have been prepared these page strips uh are shown these are the ph strips we will be using they range they have four different uh strip four different markings on here put that there four different markings on here and depending on the color of those markings we could indicate what ph it's falling into if it's fall if it falls within the range of zero this is how the coloration should be if it falls a ph of one this is the color the arrangement of the colors that we should see all the way up to ph seven then in the back it's not limited to uh zero through seven it goes from zero seven to fourteen for the higher phs so if it's in a basic solution these are the colors we should be expecting if it's an acidic solution these are the colors we should be expecting okay so let's start off with tap water so we're going to take our ph strips and we literally have to submerge it into the solution dip it again depending once more remove the excess water and now comes the fun part we have to compare this to the ph to this compared to these colors here so it's not in the acidic range it seems like it actually matches closely to the ph of 7. so we see that this color here these four colors match what should be indicating the indicator for ph of seven okay so that's tap water so tap water has a ph of seven let's go with 0.1 molar on nitric acid nitric acid should have a low ph because the name itself is telling you that it's an acid we're going to go ahead take the strip dip it in here remove the excess water now i have to compare it to this right here looks like it matches and i see so the top line is a dark purple i would say between one and two i lean more towards a ph of one so 0.1 molar nitric acid has a ph of one okay sodium carbonate so carbonate is interesting in that it is actually a it's a base right since sodium carbonate's a base we should expect to have a ph above seven this in here remove the excess water definitely a ph above seven because we're starting to see that this blue the second line is a dark pretty dark blue and also the third line so it will match the blue line now let's match the third line a pretty dark blue color very dark purple color but not light so it seems like it's actually matching the ph of 10. so 0.1 molar sodium carbonate matches a ph of oh this is a toss-up i'd go with a ph of 10. okay potassium hydroxide strong base again a ph higher than seven how much higher than seven we're about to find out it's a really dark we have some really dark colors towards the bottom so what you're seeing here is potassium hydroxide has a ph of 14. 0.1 molar potassium hydroxide ph 14. potassium chloride potassium chloride does disassociate but it's forming the the conjugate base would be the chloride ion and the conjugate acid would be the conjugate base is the chloride ion and the conjugate acid would be the potassium ion well in this case the the conjugate base the chloride ion since it the acid form of this of a chloride ion would be the hydrochloric hydrogen hcl it does not it will not go back right pretty much we have 100 dissociation from the strong acid therefore the chloride anion is not interacting with water since it's not interacting with water technically potassium chloride should be in the neutral ph should have a close ph of 7. so we're seeing the ph is actually closer to six which is fine i mean that is because maybe the water itself might be a little bit more acidic but it is really cl it falls in the range of between six and seven but i would lean more towards the ph being a rather than the ph of 7. so to test 0.1 molar potassium chloride has a ph of 6. 0.1 molar potassium sorry 0.1 molar acetic acid it's a weak acid remove excess water since it's an acid we know it should have a low ph trying to match it has a ph of looks like the ph the colors coordinate to the ph of 3. so 0.1 molar acetic acid has a ph of 3. ammonium hydroxide 0.1 molar ammonium hydroxide since we're producing the hydroxide ion hydroxide anion that should be this should be a base put my ph strips in here now we're going to compare it since it's the base ph bases have a ph greater than seven now it's just time to line it up i think you can by this you i hope you by this time you can kind of uh see the disadvantage of using these ph strips even though you do have four different lines that have that can uh indicate different colors and then match those four lines to the uh to the to the references here it's still not a hundred percent uh it's not as accurate as a using a ph meter but this is this method works fairly well as we've seen here with these lines we're seeing that the ph of 0.1 ammonium hydroxide is 10. it's leaning towards it more being more it's about a 10. so how these are pretty accurate especially if you just want to find out the ph of the solution and how close it is okay the 0.1 molar hydrochloric acid this is definitely a strong acid as we saw with the light bulbs it's a strong electrolyte so we have a hundred percent disassociation but what ph is it fall in it should be less than seven so it looks like the ph of 0 and ph of 1 are very close to it i'm going off of the top spot the top line because it's really dark red i'd say 0.1 molar hydrochloric acid is a ph of one cool all right so if you want to find out the ph of uh apple juice and you don't have a ph meter but you do have these strips we can identify the ph of apple juice based off of these strips and of course once the apple juice has been in the lab it is considered uh to have chemicals in there so we're not going to drink this apple juice now what ph does apple juice have it's definitely acidic because this top line has a dark coloration to it dark reddish coloration and it seems like the ph of apple juice kind of falls in the ph of three actually the top line is a little bit more no no no it's the ph of apple juice i will lean it so apple juice is slightly acidic so these are two experiments for lab number seven i hope you hope these were helpful to you thank you