Question 1

H-C\equiv C-H+H_{2} \xrightarrow {Pd-BaSO_{4}/Quinoline} A \xrightarrow {HCl} B\xrightarrow{aq.\ KOH}C Here,  C  is:

Accepted Answer

The complete reaction sequence is as follows: H-C\equiv C-H+H_{2} \xrightarrow {Pd-BaSO_{4}/Quinoline} H_2C=CH_2 \xrightarrow{HCl} C_2H_5Cl \xrightarrow{aq.\ KOH} C_2H_5OH A  is ethene, formed by Lindlar's catalyst. B  is ethyl chloride, formed by the addition of  HCl  to an alkene. C  is ethanol because alkyl halides react with aqueous  KOH  to give alcohols.So, the correct option is B

Question 2

The order of reactivity of alcohols towards hydrogen halide is :

Accepted Answer

Greater the stability of carbocation formed, greater is the reactivity. Benzyl carbocation is resonance stabilized. 	herefore\   tertiary > benzyl > secondary > primary Option B is correct.

Question 3

An alcohol (A) on heating with concentrated  H_{2} SO_{4}  gives alkene (B), which shows geometrical isomerism. The compound (A) is:

Accepted Answer

Since, alkene shows geometrical isomerism. So, the groups should be different on both sides of double bond.When 2-butanol is heated with conc. sulfuric acid, it forms 2-butene, which shows geometrical isomerism in the form of cis and trans isomers. CH_{3}CH_{2}CH(OH)CH_{3} \xrightarrow [conc.\ H_2SO_4] {dehydration} CH_3CH=CHCH_3

Alcohols, Phenols And Ethers