Category: Class 12

NCERT Solutions for 12th Class Chemistry:Chapter 16-Chemistry in Everyday Life EXERCISES 16.1. Why do we need to classify drugs in different ways?Ans: Drugs are classified in following different ways:(a) Based on pharmacological effect.(b) Based on action on a particular biochemical process.(c) Based on chemical structure.(d) Based on molecular targets.Each classification has its own usefulness.(а) Classification based… Continue reading NCERT Solutions for 12th Class Chemistry:Chapter 16-Chemistry in Everyday Life

NCERT Solutions for 12th Class Chemistry:Chapter 15-Polymers EXERCISES 15.1. Explain the terms polymer and monomer.Ans: Polymers are high molecular mass substances consisting of a very large number of simple repeating structural units joined together through covalent bonds in a regular fashion. Polymers are also called macromolecules. Some examples are polythene, nylon-66, bakelite, rubber, etc. Monomers are… Continue reading NCERT Solutions for 12th Class Chemistry:Chapter 15-Polymers

NCERT Solutions for 12th Class Chemistry:Chapter 14-Biomolecules EXERCISES 14.1. What are monosaccharides ?Ans: Monosaccharides are carbohydrates Which cannot be hydrolysed to smaller molecules.Their general formula is (CH2O)n Where n=3-7 These are of two types: Those which contain an aldehyde group (-CHO) are called aldoses and those which contain a keto (C=O) group are called ketoses.They are… Continue reading NCERT Solutions for 12th Class Chemistry:Chapter 14-Biomolecules

NCERT Solutions for 12th Class Chemistry:Chapter 13-Amines EXRECISES 13.1. Write IUPAC names of the following compounds and classify them into primary, secondary, and tertiary amines. (i) (CH3)2 CHNH2 (ii) CH3(CH2)2NH2 (iii) CH3NHCH(CH3)2(iv) (CH3)3 CNH2 (v) C6H5NHCH3(vi) (CH3CH2)2NCH3(vii)m-BrC6H4NH2Ans: (i) Propan-2-amine(1°)(ii) Propan-1-amine (1°),(iii) N-Methylpropan-2-amine (2°).(iv) 2-Methylpropan-2-amine(l°)(v) N-MethylbenzenamineorN-methylaniline(2°)(vi) N-Ethyl-N-methylethanamine (3°)(vii) 3-Bromobenzenamine or 3-bromoaniline (1°) 13.2. Give one chemical test to distinguish between the following pairs… Continue reading NCERT Solutions for 12th Class Chemistry:Chapter 13-Amines

NCERT Solutions for 12th Class Chemistry: Chapter 12-Aldehydes Ketones and Carboxylic Acids EXERCISES 12.1. What is meant by the following terms? Give an example of the reaction in each case.(i) Cyanohydrin(ii) Acetal(iii) Semicarbazone(iv) Aldol(v) Hemiacetal(vi) Oxime(vii) Ketal(viii) Imine(ix) 2,4-DNP derivative(x) Schiff’s base.Ans: (i) Cyanohydrin: gem-Hydroxynitriles, i.e., compounds possessing hydroxyl and cyano groups on the same carbon… Continue reading NCERT Solutions for 12th Class Chemistry: Chapter 12-Aldehydes Ketones and Carboxylic Acids

NCERT Solutions for 12th Class Chemistry: Chapter 11-Alcohols Phenols and Ether EXERCISES 11.1. Write IUPAC names of the following compounds: Ans: (i) 2,2,4-Trimethylpentan-3-o(ii) 5-Ethylheptane-2,4-dioI(iii) Butane-2,3-diol(iv) Propane-1,2,3-triol(v) 2-Methylphenol(vi) 4-Methylphenol(vii) 2,5-DimethylphenoI(viii) 2,6-Dimethylphenol(ix) 1-Methoxy-2-methylpropane(x) Ethoxybenzene(xi) 1-Phenoxyheptane(xii) 2-Ethoxybutane 11.2. Write structures of the compounds whose IUPAC names are as follows:(i)2-Methylbutan-2-ol(ii)l-Phcnylpropan-2-ol(iii)3,5-DimethyIhexane-l,3,5-triol(iv)2,3-Dicthylphenol(v)1-Ethoxypropane(vi)2-Ethoxy-3-methylpentane(vii) Cyclohexylmethanol(viii) 3-Cyclohexylpcntan-3-ol(ix)Cyclopcnt-3-en-l-ol(x)4-ChIoro-3-ethylbutan-l-olAns: 11. 3. (a) Draw the structural formulas and write… Continue reading NCERT Solutions for 12th Class Chemistry: Chapter 11-Alcohols Phenols and Ether

NCERT Solutions for 12th Class Chemistry: Chapter 10-Haloalkanes and Haloarenes EXERCISES 10.1. Name the following halides according to the IUPAC system and classify them as alkyl, allyl, benzyl (primary, secondary, tertiary), vinyl, or aryl halides:(i)(CH3)2CHCH(Cl)CH3(ii) CH3CH2CH(CH3)CH(C2H5)CI(iii) CH3CH2C(CH3)2CH2I(iv)(CH3)3CCH2CH(Br)C6H5(v)CH3CH(CH3)CH(Br)CH3(vi)CH3C(C2H5)2CH2Br(vii)CH3C(Cl)(C2H5)CH2CH3(viii)CH3CH=C(CI)CH2CH(CH3)2(ix)CH3CH=CHC(Br)(CH3)2(x)P-CIC6H4CH2CH(CH3)2(xi)m-ClCH2C6H4CH2C(CH3)3(xii)o-Br -C6H4CH (CH3)CH2CH3Ans: (i) 2-Chloro-3methylbutane, 2° alkyl halide(ii) 3-Chloro-4methyl hexane, 2° alkyl halide(iii) 1 -Iodo-2,2-dimethylbutane, 1 ° alkyl halide(iv) l-Bromo-3,… Continue reading NCERT Solutions for 12th Class Chemistry: Chapter 10-Haloalkanes and Haloarenes

NCERT Solutions for 12th Class Chemistry: Chapter 9-Coordination Compounds EXERCISES 9.1. Explain the bonding in coordination compounds in terms of Werner’s postulates.Ans: The main postulates of Werner’s theory of coordination compounds are as follows:(a)Metals possess two types of valencies called(i) primary valency which are ionisable; (ii) secondary valency which are non- ionisable(b)Primary valency is satisfied by… Continue reading NCERT Solutions for 12th Class Chemistry: Chapter 9-Coordination Compounds

NCERT Solutions for 12th Class Chemistry: Chapter 8-The d and f Block Elements EXERCISES 8.1. Write down the electronic configuration of (i) Cr3+ (ii) Pm3+ (iii) Cu+ (iv) Ce4+(v) Co2+ (vi) Lu2+(vii) Mn2+ (viii) Th4+.Sol: (i) Cr3+ = [Ar]183d3(ii)Pm3+ = [Xe]54 4f4(iii)Cu+ = [Ar]18 3d10(iv)Ce4+ = [Xe]54(v)Co2+ = [Ar]18 3d7(vi)Lu2+ = [Xe]54 4f14 5d1(vii) Mn2+ = [Ar]18 3d5 (viii)Th4+= [Rn]86 8.2. Why are Mn2+ compounds more stable than Fe2+ towards oxidation to their+3 state?Sol: Electronic configuration of Mn2+ is… Continue reading NCERT Solutions for 12th Class Chemistry: Chapter 8-The d and f Block Elements

NCERT Solutions for 12th Class Chemistry: Chapter 7-The p Block Elements EXERCISES 7.1. Discuss the general characteristics of Group 15 elements with reference to their electronic configuration, oxidation state, atomic size, ionisation enthalpy and electronegativity.Sol: In group 15 of the Periodic Table, the elements, nitrogen (7N), phosphorus (15P), arsenic (33As), antimony (51Sb) and bismuth (83Bi) are… Continue reading NCERT Solutions for 12th Class Chemistry: Chapter 7-The p Block Elements