Question

Identify the bronsted-lowry acid and the bronsted-lowry base in this reaction on the left side of each of the following equations, and also identify the conjugate acid and conjugate base of each on the right side.
mathrm { NH } _ { 4 } ^ { + } ( a q ) + mathrm { CN } ^ { - } ( a q ) rightleftharpoons mathrm { HCN } ( a q ) + mathrm { NH } _ { 3 } ( a q )

Answer 1

Answer: $NH_4^+$ is an acid, $CN^-$ is a base, $NH_3$ is conjugate base and $HCN$ is conjugate acid

Explanation:

According to Bronsted and Lowry's theory:

An acid is defined as a proton donor while a base is defined as a proton acceptor.

In a chemical reaction, an acid loses a proton to form a conjugate base while a base accepts a proton to form conjugate acid.

For the given chemical reaction:

$NH_4^+(aq)+CN^-(aq)\rightleftharpoons HCN(aq)+NH_3(aq)$

$NH_4^+$ is losing a proton thus it is an acid to form $NH_3$ which is its conjugate base

$CN^-$ is gaining a proton thus it is a base to form $HCN$ which is its conjugate acid

Hence, $NH_4^+$ is an acid, $CN^-$ is a base, $NH_3$ is conjugate base and $HCN$ is conjugate acid