MCQs on Organic Chemistry for NEET

Organic Chemistry is the branch of science dealing with the study of carbon-containing compounds. Carbon has a unique property of catenation due to which it forms C-C covalent bond leading to long carbon straight-chain and branched-chain compounds. It also forms a covalent bond with H, O, N, S, P and halogens, resulting in a wide variety of compounds. Organic compounds are vital to life. The genetic material, proteins, medicines, fuels are all organic compounds.

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

(a) crystallisation

(b) chromatography

(c) sublimation

(d) steam distillation

Answer: (d)

2. 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

Answer: (a)

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

(a) -COOH

(b) -SO3H

(c) -NO2

(d) -CN

Answer: (c)

4. 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

Answer: (b)

5. The correct order of increasing nucleophilicity is

(a) Cl < Br < I

(b) Br < Cl < I

(c) I < Br < Cl

(d) I < Cl < Br

Answer: (a)

6. Homologous series of alkanols have general formula

(a) CnH2nO2

(b) CnH2nO

(c) CnH2n+1O

(d) CnH2n+2O

Answer: (d)

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

(a) Benzyl chloride

(b) Chlorobenzene

(c) Ethyl chloride

(d) Isopropyl chloride

Answer: (a)

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

(a) Crystallisation

(b) Chromatography

(c) Sublimation

(d) Distillation

Answer: (c)

9. How many structural isomers are possible if one hydrogen in diphenyl methane is replaced by chlorine?

(a) 8

(b) 4

(c) 7

(d) 6

Answer: (b)

10. 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

Answer: (d)

 

Leave a Comment

Your email address will not be published. Required fields are marked *