Chemistry Chapter 15 Entry Test MCQs
Topic 15
Electrophile + Nucleophile
1. Nucleophilicity order is correctly represented by:
a. CH3– ≃ NH2– >OH– ≃ F–
b. CH3– < NH2– < OH– < F–
c. NH2–< F– < OH– < CH3
d. CH3– > NH2– > OH– > F–
2. Which one is strong nucleophille?
a. I–1
b. Br–1
c. Cl–
d. NH3
3. Which of the following is ambident nucelophile?
a. OH–
b. NH2–
c. SCN–
d. Both A and C
4. Strongest nucleophile is
a. C6H5O–
b. RNH2
c. CH3O–
d. ROH
5. Which behaves both as a nucleophile and electrophile
a. CH3CN
b. CH3NH2
c. CH3OH
d. CH3Cl
6. Which one of the following is not a nucleophile?
a. H2S
b. H2O
c. NH3
d. CO2
7. Which one is strongest base?
a. Cl–1
b. I–1
c. Br–1
d. NH3
8. Select a nucleophile from the following:
a. Carbanion
b. Nitronium ion
c. Ammonium ion
d. Carbonium ion
Reactions of Alkyl halides
9. To prepare a pure sample of n-hexane using sodium metal as one reactant, the other reactant will be
a. Ethyl bromide and n-butyl bromide
b. n-propyl bromide
c. Methyl bromide and n -pentyl chloride
d. Ethyl chloride and n-butyl chloride
10. Iodoethane reacts with sodium in the presence of dry ether. The product is
a. Butene
b. Pentane
c. Butane
d. Propane
11. Alkyl iodide is reactive due to:
a. The presence of I atom
b. Primary nature of alkyl halides
c. secondary nature of alkyl halides
d. The low dissociation energy of C-I bond
12. Preparation of alkyl halides in laboratory is least preferred by
a. Addition of hydrogen halides to alkenes
b. Treatment of alcohols
c. Direct halogenation of alkane
d. Halide exchange
13. The starting substance for preparation of CH3I is
a. CH3CHO
b. CH3OH
c. (CH3) 2CO
d. C2H5OH
14. A mixture of two organic chlorine compounds was treated with sodium metal in ether solution. Isobutane was obtained as a product. The two chlorine compounds are
a. Methyl chloride and ethyl chloride
b. Methyl chloride and propyl chloride
c. Isopropyl chloride and ethyl chloride
d. Isopropyl chloride and methyl chloride
15. The reactivity of ethyl chloride is
a. More than that of benzyl chloride
b. More or less equal to that of benzyl chloride
c. Less than that of chlorobenzene
d. More or less equal to that of chlorobenzene
16. Ethyl bromide can be converted into ethyl alcohol by
a. Boiling with an alcoholic solution of KOH
b. Heating with dilute hydrochloric acid and zinc
c. Refluxing methanol
d. The action of moist KOH
17. Reaction of ethyl chloride with sodium leads to
a. n-butane
b. Ethane
c. n-pentane
d. Propane
18. Chlorobenzene is
a. More reactive than ethyl bromide
b. Less reactive than benzyl chloride
c. More reactive than isopropyl chloride
d. Nearly as reactive as methyl chloride
19. The reactivities of methyl chloride, propyl chloride and chlorobenzene are in the order
a. Methyl chloride > chlorobenzene > propyl chloride
b. Methyl chloride > propyl chloride > chlorobenzene
c. Chlorobenzene > propyl chloride > methyl chloride
d. Propyl chloride > methyl chloride > chlorobenzene
20. Dehydrohalogenation of an alkyl halide is
a. Elimination reaction
b. Addition reaction
c. Oxidation reaction
d. Substitution reaction
21. 2-bromopentane is heated with potassium ethoxide in ethanol. The major product obtained is
a. trans 2-pentene
b. 1-Pentene
c. 2-ethoxypentane
d. cis 2-pentene
22. Which is the best solvent to use for the solvolysis reaction of t- butyl chloride?
a. Formic acid
b. Water
c. Heptane
d. Carbon tetrachloride
23. What will be products when reactants are alcohol & thionyl chloride in presence of pyridine?
a. RCl + SO2 + H2O
b. RCl + S + HCl
c. RCl + S + H2O
d. RCI + SO2 + HCl
24. Which C-X bond has the highest bond energy per mole?
a. C-Br
b. C-F
c. C-I
d. C-Cl
25. Ethyl chloride with nascent hydrogen produces
a. Propane
b. Methane
c. Butane
d. Ethane