[Music] carbon and its compounds carbon compounds play an important role in our day-to-day life things like toothpaste soap Cosmetics medicines clothes paper or carbon compounds even the bread we eat is a carbon compound if we burn the bread we get a black substance that is nothing but carbon the amount of carbon present in Earth is very less the Earth's crust has 0.02% of carbon in the form of carbonates hydrogen carbonates coal and petroleum the atmosphere has 0.3% of carbon dioxide we have already learned about ionic compounds let us see some important differences between ionic compounds and carbon compounds carbon compounds are poor conductors of electricity that means they do not conduct the electricity whereas ionic compound are good conductors of electricity the boiling points and melting points of carbon compounds are less compared to ionic compounds for example the boiling point of acetic acid which is a carbon compound is about 118° CSI whereas the boiling point of an ionic compound like sodium chloride is, 143° C in carbon compounds the force of attraction between the molecules is not not very strong whereas in the ionic compounds the force of attraction between the molecules is very strong the bonding in carbon compound does not give rise to any ions the bonding in ionic compounds gives rise to ions bonding in carbon compounds the atomic number of carbon is six the outermost shell has four electrons so its valency is four generally ionic compounds attain the noble gas config duration by either losing or gaining electrons but carbon cannot do that let us see why if carbon gains four electrons it would be difficult for the nucleus with six protons to hold on to 10 electrons if carbon has to lose four electrons it would require a large amount of energy to remove four electrons then it turns into a carbon Caton with six protons in its nucleus holding on to just two electrons so losing and gaining of electrons does not work with carbon to make bonds so carbon cannot form ionic bond covalent bond carbon make calent bond with other carbon atoms or with atoms of other elements before we see the calent bond in carbon compounds first study the covalent bond formation in hydrogen in oxygen and in nitrogen molecules calent bond a calent bond is a chemical Bond formed by the sharing of electrons between two non-metal atoms let us see calent Bonds in hydrogen oxygen and in nitrogen molecules hydrogen atom has a single electron in its K shell it attains the nearest noble gas helium's configuration by sharing its single electron with another hydrogen atom two hydrogen atoms share their single electrons to form a molecule of hydrogen since only one electron is shared by each atom a single calent bond is formed between them oxygen has six electrons in its L shell it needs two electrons to complete its octet so each atom of oxygen contributes two electrons that means a total of four electrons are commonly shared by the two oxygen atoms then it forms a double bond nitrogen in the formation of nitrogen molecule each nitrogen atom contributes three electrons means total six electrons are shared by two nitrogen atoms here a triple bond is formed this is ammonia molecule one nitrogen atom forms covalent bond with three hydrogen atoms to forms this molecule here all the three bonds are single bonds this is methane molecule CH4 one carbon atom forms calent bond with four hydrogen atoms here also all the four bonds or single bonds versatile nature of carbon carbon is a versatile element due the nature of the covalent bond carbon is able to form millions of compounds let us see the two main factors which make the carbon a versatile element one catenation carbon has the unique ability to form bonds with other atoms of carbon this gives rise to the formation of large molecules this property is called catenation let's see its definition cenation is the self-linking of atoms of an element to create chains and Rings due to this property carbon forms large molecules in the form of long linear chains branched chains and ring chains in addition carbon atoms may be linked by single double and triple bonds carbon compounds with single Bond are saturated carbon compounds carbon compounds with double and triple bonds are called unsaturated carbon compounds does only carbon exhibit catenation no many other elements show catenation for example silicon silicon form chain compounds up to a length of seven or eight atoms these compounds are very reactive and unstable whereas carbon can form compounds with a very large number of carbon atoms linked to each each other these compounds are very stable because the carbon carbon bond is very strong number two the second factor for the versatility of carbon is its valency a carbon atom can form bonds with four other carbon atoms or with other elements whose valency is one carbon can bond with oxygen hydrogen nitrogen sulfur chlorine Etc these compounds will have specific properties the bond that carbon makes with other elements is very strong which makes these compounds exceptionally strong the reason for the strength of the bonds of carbon is due to its smaller atomic size due to the small size of the carbon atoms the nucleus is close to the shared pair of electrons and it holds these electrons strongly the bonds formed by elements having bigger atomic size have weak bonds so these are the reasons for The Versatile nature of carbon saturated and unsaturated carbon compounds we already learned that compounds with single Bonds in their structure are saturated compounds and compounds with double or triple bonds are unsaturated compounds C2 H6 ethane is it saturated or unsaturated let us draw its structure to know whether it is saturated or unsaturated first link carbon with carbon using a single Bond then link three hydrogens with one carbon and three with the other the valencies of carbon and hydrogen are satisfied and no double bonds are formed so this is a saturated compound now let us write the structure of C2 H4 Ethan first link carbon with carbon using a single Bond then link two hydrogens with one carbon and two hydrogens with the other with single bonds the valences of hydrogen are satisfied but the valences of carbon atoms are not satisfied now draw another line between the two carbon atoms now the carbon valency is satisfied here this compound has got a double bond so it is an unsaturated compound in the same way let us draw the structure for C2 H2 ethine here we need to draw a triple bond between the two carbon atoms so this is also an unsaturated compound so we understood that carbon compounds with single bonds are saturated carbon compounds and carbon compounds with double or triple bonds are unsaturated carbon compounds unsaturated carbon compounds are more reactive than the saturated compounds chains branches and Rings butane C4 h10 we can write it structure in two ways like like this and like this this is the stride chain structure of butane and this is the branched chain structure of butane both the structures satisfies the valency of carbon and hydrogen both of them have the same formula we can call these two compounds as structural isomers the compounds with identical molecular formula but different structures are called structural isomers in addition to strip chain and branched chain structures some carbon compounds formed ring structures such compounds are called cyclic carbon compounds for example cyclohexene C6 h12 this is a saturated cyclic compound Benzene C6 H6 this is an unsaturated cyclic carbon compound so the compounds that contain only carbon and hydrogen in them are called hydrocarbons the saturated hydrocarbons are called alkanes the unsaturated hydrocarbons with one or more double bonds are called alkenes the unsaturated hydrocarbons with one or more triple bonds are called all kinds carbon compounds and their functional groups carbon can form bonds with other elements like chlorine bromine oxygen nitrogen and sulfur and forms new compounds new carbon compounds are formed when a hydro hen atom of the hydrocarbon chain is replaced by an element the element that replaces the hydrogen atom is called as hyro atom for example here a hydrogen atom of this compound is replaced by chlorine atom so here chlorine is the hetro atom these hetro atoms forms the functional groups of the compounds sometimes hetro atoms pair up with some other atoms and form groups for example here oxygen is the Hydro atom it forms various functional groups like alcohol alahh Ketone carboxilic acid Etc this is chlorine here chlorine is the functional group this is ethanol since o is the functional group it is an alcohol this is acet alide Cho is the functional group it is an alhy this is acetone Co is the functional group it is a ketone the properties of the newly formed compound will be totally dependent on the functional group of the compound when writing the structure of functional group alone the free valencies of the whole group is shown by a single line homologous series ch3 o this is methanol it has one carbon in it C2 H5 this is ethanol it has two carbons in it C3 H7 o it is propenol it has three carbons in it C4 H9 o this is butanol it has four carbons these four compounds have oh as the functional group and are called as alcohols even though the number of carbon atoms in each of these compound is different they have similar chemical properties such series of compounds are called homologous series the series of compounds in which the same functional group substitutes for hydrogen in a carbon chain is called a homologous series let us see the homologous series of alkanes methane ethane propane butane the difference between the each of these compounds is the difference in the number of units of ch2 this is the homologous series of alkenes ethine propene buttin pentin in alkanes alkenes and alkes we can observe that there is a specific ratio of carbon and hydrogen is maintained for example in alkenes CN H2 and pattern is observed if n is equal to 2 then the compound will be C2 H2 into 2 that is C2 H4 in any homologous series we will observe the gradual increase in the molecular mass if the molecular mass increases the melting and boiling points also increases whereas the solubility of the compounds decreases with the increase in the molecular mass that means the physical properties of a homologous series depends upon their molecular mass whereas the chemical properties of a homologous series solely determined by the functional group nomenclature of carbon compounds the carbon compounds are named on the basis of three things one the number of carbon atoms in the main carbon chain two the type of bonds present in the compound that means single double or triple bonds three the functional group present in that compound the name of a carbon compound is made up of two parts a Prix and a suffix prefix is the first part of the name it is dependent on the number of carbon atoms present in the carbon chain if the compound has one carbon the name begins with meth if two carbons it begins with Y three carbons it begins with prop and four carbons it begins with buot if the hydrocarbon chain contains all single bonds then the suffix becomes a that is methane ethane propane butane Etc if the hydrocarbon chain contains double bonds then the suffix becomes in that is methan ethine propene buttine if the hydrocarbon chain contain triple bond then the suffix becomes ion that is methine ethine propine buttine ETC if the carbon chain has a functional group then the suffix changes according to the functional group if the functional group of a three carbon compound is alcohol then the suffix becomes all for example propanol if the functional group is Ketone then it becomes propanone if the functional group is alhy then this compound becomes propenol if the functional group is carboxilic acid then this becomes propanoic acid if the functional group is Chlor then it becomes chloropropane and if the functional group is bromine then it becomes bromopropane chemical properties of carbon compounds combustion reactions most of the carbon compounds burn in presence of oxygen and produces carbon dioxide large amounts of heat and light are also released in this combustion reaction carbon plus oxygen gives rise to carbon dioxide plus heat plus light if saturated hydrocarbons like butane that is the cooking gas is burned in presence of sufficient amount of oxygen it gives a clean blue flame with no suit if the saturated hydrocarbons are giving an yellow flame that means it indicates that there is a limited supply of oxygen to that combustion reaction it leads to incomplete burning of the fuel and gives out yellow flame if unsaturated hydrocarbons like vegetable oils are burnt yellow color flame is produced with black color soit in oil lamps kerosene stows firewood stows black suit is formed indicating the incomplete combustion of fuels fuels like coal and petroleum contain some amount of nitrogen and sulfur in them combustion of these substances releases oxides of sulfur and nitrogen into the air which leads to air pollution oxidation the alcohols when heated with some oxidizing agents they get oxidized and converted to carboxilic acids for example when ethy alcohol is heated with alkaline km4 or acidified K2 cr207 it produces acetic acid here alkaline potassium permanganate or acidified potassium dichromate adds oxygen to the alcohols and make them into acids hence these substances are called oxidizing agents the substances that are capable of adding oxygen to other substances are known as oxidizing agents addition reaction vegetable oils have long unsaturated carbon chains animal fats have chains of saturated fatty acid unsaturated fats can be converted into saturated fats with the help of addition reaction when hydrogen is added to the unsaturated fats in presence of a catalyst like nickel the unsaturated fats turns into saturated fats vanaspati ghee is manufactured by using this addition reaction this process is called hydrogenation of vegetable oils catalysts are the substances that cause a reaction to occur at a different rate without the reaction itself being affected now substitution reaction substitution reactions in carbon compounds are single displacement reactions they occur when saturated hydrocarbons react with chlorine in presence of sunlight chlorine is more reactive than hydrogen atoms so it can displace them from saturated hydrocarbons CH4 plus cl2 gives rise to ch3 CL plus HCL in presence of sunlight some important carbon compounds ethanol and ethanolic acid properties of ethanol one ethanol is a liquid at room temperature it is an active ingredient in alcoholic drinks consumption of these alcoholic drinks is harmful to one's Health ethanol is a good solvent and used in the manufactur of tinure iodin cough syrups and many tonics nowadays ethanol is added to fuel like petrol as an eco-friendly measure properties of ethanolic acid ethanoic acid belongs to the group of carboxilic acids it is also called as acetic acid carboxilic acids are weaker acids when compared to Mineral acids like HCL 5 to 8% of acetic acid in water is called as vinegar it is used as a preservative in pickles the ethanoic acid freezes at room temperature during winter in cold climates so it is called as glacial atic acid reactions of ethanoic acid esterfication reaction Esters are usually formed by the reaction between an alcohol and an acid ethanoic acid reacts with an absolute ethanol in the presence of an acid Catalyst to give an ester ethanoic acid plus ethanol gives rise to Esther in presence of an acid esters are sweet smelling substances they are used in the manufacture of perfumes and flavoring agents the Esters can be converted back to alcohol and sodium salt of carboxilic acid by treating with an alkal like sodium hydroxide this reaction is is used in the manufacture of soaps and is called as saponification reaction soaps are sodium or potassium salts of longchain carboxilic acids reaction with a base ethanoic acid reacts with sodium hydroxide to give a salt called sodium ethanoate sodium hydroxide plus acetic acid gives rise to sodium ethano plus water reaction with carbonates and hydrogen carbonates if ethanoic acid reacts with carbonates and hydrogen carbonates to give rise to a salt called sodium acetate carbon dioxide and water soaps and detergents if a shirt with dirt is simply rinsed in plain water some dirt may go away but it will not be completely clean because most of the dirt is oily in nature and cannot be simply washed away by plain water soaps and detergents are used to clean the oily dirt the molecules of soap are sodium or potassium salts with long chain carboxilic acids so one of the end of the soap molecule is ionic in nature it is hydrophilic means attracts water molecules whereas the carbon chain is hydrophobic in nature that means it reacts with the oil so carbon chains hold the oily dirt whereas the ionic can get dissolved in the water th the soap mole ules are arranged in specific structures called mels when the clothes are rinsed by applying mechanical force these soap mels helps in pulling out the dirt and makes the cloths clean [Music]