Organic Chemistry – Some Basic Principles and Techniques 1. Which is the best-suited method for the separation of para and ortho-nitropheno...
Organic Chemistry – Some Basic Principles and Techniques
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 a 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 diphenylmethane 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
COMMENTS