Question

Fill in the left side of this equilibrium constant equation for the reaction of nitrous acid (HNO_2) with water.

__________= K_a

Answer 1

1. The equilibrium equation for the reaction between nitrous acid (HNO2) and water (H2O) is given below:

HNO2(aq) + H2O(l) <=> H3O+(aq) + NO2- (aq)

2. Ka = [H3O+] [NO2-] / [HNO2]

Step-by-step explanation:

1. Step 1:

The reaction of nitrous acid HNO2 acid with water.

When nitrous acid react with water, it will produce hydronium ion (H3O+) and the corresponding nitrite ion (NO2-). This is so because an acid will dissolves in water to produce hydronium ion as the only positive ion. The equation is illustrated below:

HNO2(aq) + H2O(l) <=> H3O+(aq) + NO2- (aq)

2. Step 2:

Writing the Ka for the above equation. This is illustrated below:

The Ka is given by:

Ka = [H3O+] [NO2-] / [HNO2]

Answer 2

`Ka=([H^+][NO_2^-])/([HNO_2])`

Step-by-step explanation:

The reaction

The reaction of nitrous acid with water is a dissociation reaction of an acid:

`HNO_2(aq) + H_2O(l) \longrightarrow H^+(aq) + NO_2^-(aq) + H_2O(l)`

`HNO_2(aq) \longrightarrow H^+(aq) + NO_2^-(aq)`

The Ka equation

`Ka=([H^+][NO_2^-])/([HNO_2])`