Question

A primary haloalkane (x) if allowed to reacts with KCN yields a compound (y) which on acidic hydrolysis gave propanoic acid. Identify (x) and (y)

Answer 1

Given:

X = primary haloalkane

X + KCN → Y

Y on acidic hydrolysis gave propanoic acid

To Find:

X and Y

Explanation:

let us assume that that the X is R-x

then on reaction with KCN, it will form R-CN

X + KCN → Y

thus here Y = R-CN

Now, Y on acidic hydrolysis gave propanoic acid

R-CN + H2O/acid → R-COOH

Also, we know that,

R-COOH = CH3-CH2-COOH ( propanoic acid)

Thus, R = CH3-CH2

from this

Y = CH3-CH2-CN  ( propane nitrile)

X = CH3-CH2-x  where x = Cl/Br/I