Choose the best answer: Chemistry:Hydrocarbons

Chemistry: Hydrocarbons

Evaluation

Choose the best answer

1. The correct statement regarding the comparison of staggered and eclipsed conformations of ethane, is

a) the eclipsed conformation of ethane is more stable than staggered conformation even though the eclipsed conformation has torsional strain.

b) the staggered conformation of ethane is more stable than eclipsed conformation, because staggered conformation has no torsional strain.

c) the staggered conformation of ethane is less stable than eclipsed conformation, because staggered conformation has torsional strain.

d) the staggered conformation of ethane is less stable than eclipsed conformation, because staggered conformation has no torsional strain.

2. C2H5 Br + 2Na   --- dry ether→ C4H10 + 2NaBr

The above reaction is an example of which of the following

a) Reimer Tiemann reaction

b) Wurtz reaction

c) Aldol condensation

d) Hoffmann reaction

3. An alkyl bromide (A) reacts with sodium in ether to form 4, 5– diethyloctane, the compound (A) is

a) CH3 (CH2)3 Br

b) CH3(CH2)5 Br

c) CH3(CH2)3 CH(Br)CH3

d) 

Ans: d

4. The C – H bond and C – C bond in ethane are formed by which of the following types of overlap

a) sp3 – s and sp3 – sp3

b) sp2 – s and sp2 – Sp2

c) sp – sp and sp – sp

d) p – s and p – p

5. In the following reaction,

The major product obtained is

Ans: c

6. Which of the following is optically active

a) 2 – methyl pentane

b) citric acid

c) Glycerol

d) none of of these

7. The compounds formed at anode in the electrolysis of an aquous solution of potassium acetate are

a) CH4 and H2

b) CH4 and CO2

c) C2H6 and CO2

d) C2H4 and Cl2

8. The general formula for cyclo alkanes

a) CnHn

b) CnH2n

c) CnH2n–2

d) CnH2n+2

9. The compound that will react most readily with gaseous bromine has the formula

a) C3H6

b) C2H2

c) C4H10

d) C2H4

10. Which of the following compounds shall not produce propene by reaction with HBr followed by elemination (or) only direct elimination reaction

a) 

b) CH3 – CH2 – CH2 – OH

c) H2C = C = 0

d) CH3 – CH2 – CH2Br

11. Which among the following alkenes on reductive ozonolysis produces only propanone ?

a) 2 – Methyl propene

b) 2 – Methyl but – 2 – ene

c) 2, 3 – Dimethyl but – 1 – ene

d) 2, 3 – Dimethyl but – 2 – ene

12. The major product formed when 2 – bromo – 2 – methyl butane is refluxed with ethanolic KOH is

a) 2 – methylbut – 2 – ene

b) 2 – methyl butan – 1 – ol

c) 2 – methyl but – 1 – ene

d) 2 – methyl butan – 2 – ol

13. Major product of the below mentioned reaction is,

a) 2–chloro –1– iodo – 2 – methyl propane

b) 1–chloro–2–iodo–2–methylpropane

c) 1,2 – dichloro – 2 – methyl propane

d) 1, 2 – diiodo – 2 – methyl propane

14. The IUPAC name of the following compound is

a) trans–2–chloro–3–iodo – 2 – pentane

b) cis–3 – iodo – 4 – chloro – 3 – pentane

c) trans–3–iodo–4–chloro – 3 – pentene

d) cis–2 – chloro – 3 – iodo – 2 – pentene

15. Cis – 2 – butene and trans – 2 – butene are

a) conformational isomers

b) structural isomers

c) configurational isomers

d) optical isomers

16. Identify the compound (A) in the following reaction

Ans: a

17. 

a) Zn

b) Conc H2SO4

c) alc. KOH

d) dil H2SO4

18. Consider the nitration of benzene using mixed con H2SO4 and HNO3 if a large quantity of KHSO4 is added to the mixture, the rate of nitration will be

a) unchanged

b) doubled

c) faster

d) slower

19. In which of the following molecules, all atoms are co-planar

d) both (a) and (b)

20 . Propyne on passing through red hot iron tube gives

Ans: a

21. 

Ans:d

22. Which one of the following is non aromatic ?

Ans: d

23. Which of the following compounds will not undergo Friedal – crafts reaction easily ?

a) Nitro benzene

b) Toluene

c) Cumene

d) Xylene

24. Some meta-directing substituents in aromatic substitution are given. Which one is most deactivating ?

a) – COOH

b) – NO2

c) – C ≡ N

d) – SO3H

25. Which of the following can be used as the halide component for friedal - crafts reaction ?

a) Chloro benzene

b) Bromo benzene

c) chloro ethene

d) isopropyl chloride

26.  Analkane is obtained by decarboxylation of sodium propionate. Same alkane can be prepared by

a) Catalytic hydrogenation of propene

b) action of sodium metal on iodomethane

c) reduction of 1 – chloro propane

d)  reduction of bromomethane

27. Which of the following is aliphatic saturated hydrocarbon

a) C8H18

b) C9H18

c) C8H14

d) All of these

28. Identify the compound 'Z' in the following reaction

a) Formaldehyde

b) Acetaldehyde

c) Formic acid

d) none of these

29. Peroxide effect (Kharasch effect) can be studied in case of

a) Oct – 4 – ene

b) hex – 3 – ene

c) pent – 1 – ene

d) but – 2 – ene

30. 2 – butyne on chlorination gives

a) 1 – chloro butane

b) 1, 2 – dichloro butane

c) 1, 1, 2, 2 – tetrachlorobutane

d) 2, 2, 3, 3 – tetra chloro butane