Organic Chemistry MCQs

Organic Chemistry is the field of science focused on studying carbon-containing compounds. Carbon’s unique ability for catenation allows it to form C-C covalent bonds, leading to the creation of long straight-chain and branched-chain compounds. Additionally, carbon forms covalent bonds with hydrogen, oxygen, nitrogen, sulfur, phosphorus, and halogens, resulting in a vast array of compounds. Organic compounds are essential to life, as they include genetic material, proteins, medicines, and fuels.

Find the incorrect statement for a nucleophile.

(a) A nucleophile is a Lewis acid
(b) Nucleophiles do not seek electron
(c) Ammonia is a nucleophile
(d) Nucleophiles attack low electron density sites

(a) A nucleophile is a Lewis acid

Which of the following methods is best suited for the separation of a mixture containing naphthalene and benzoic acid?

(a) Crystallization
(b) Chromatography
(c) Sublimation
(d) Distillation

(c) Sublimation

Which is the best-suited method for the separation of para and ortho-nitrophenols from a 1:1 mixture?

(a) crystallisation
(b) chromatography
(c) sublimation
(d) steam distillation

(d) steam distillation

Find the compound which undergoes nucleophilic substitution reaction exclusively by an SN1 mechanism.

(a) Benzyl chloride
(b) Chlorobenzene
(c) Ethyl chloride
(d) Isopropyl chloride

(a) Benzyl chloride

Which among the following is the most deactivating meta-directing group in aromatic substitution reaction?

(a) -COOH
(b) -SO3H
(c) -NO2
(d) -CN

(c) -NO2

Ammonia evolved from 0.75 g of the soil sample in the Kjeldahl’s method for nitrogen estimation neutralises 10 ml of 1M H2SO4. Find the percentage of nitrogen present in the soil.

(a) 35.33
(b) 37.33
(c) 43.33
(d) 45.33

(b) 37.33

Why do we boil the extract with conc. HNO3 in Lassaigne’s test for halogens?

(a) to increase the concentration of NO3– ions
(b) to increase the solubility product of AgCl
(c) it increases the precipitation of AgCl
(d) for the decomposition of Na2S and NaCN formed

(d) for the decomposition of Na2S and NaCN formed

Homologous series of alkanols have a general formula

(a) CnH2nO2
(b) CnH2nO
(c) CnH2n+1O
(d) CnH2n+2O

(d) CnH2n+2O

The correct order of increasing nucleophilicity is

(a) Cl– < Br– < I–
(b) Br– < Cl– < I–
(c) I– < Br– < Cl–
(d) I– < Cl– < Br–

(a) Cl– < Br– < I–

How many structural isomers are possible if one hydrogen in diphenylmethane is replaced by chlorine?

(a) 8
(b) 4
(c) 7
(d) 6

(b) 4