# Write the chemical equation for the reaction of carbonic acid (h2co3) with water.

## General guidance

Concepts and reason
One or more reactants combining together to form a product is called chemical reaction. Acid dissociation constant gives the strength of an acid in a solution. The strength of the acid is represented by the equilibrium constant expression. After completing the given equation, the acid dissociation constant expression should be written for the equation.

Fundamentals

The weak acid dissociates in water and forms its conjugate acid and base. This reaction is an equilibrium reaction. The dissociation of acid in water at equilibrium can be written as:

The dissociation of a weak acid () in water gives its conjugate Base () and water (base) gives its conjugate acid ().

- Equilibrium arrow. In equilibrium, the concentration of reactants and products cannot be changed with respect to time.

is an equilibrium constant expression used for this kind of (acid –base dissociation) reaction to determine the strength of the acid in equilibrium.

is calculated by the ratio of the concentration of reactants and concentration of the product.

## Step-by-step

### Step 1 of 2

The reaction of carbonic acid with water:

Chemical equation for the reaction of carbonic acid with water:

The dissociation of a weak acid () in aqueous solution () gives conjugate acid () and conjugate base ().

### Step 2 of 2

The reaction is:

The acid – dissociation constant is the ratio of the concentration of products and concentration of reactants . [] is constant. Therefore, the final should not contain []. Therefore, option (a) is wrong.

In option (b), of reactants and product is reversed. Therefore, it is wrong.

In option (c), is reversed and there is no concentration. Therefore, it is wrong.

In option (d), it satisfies the concentration of. Therefore, it is a correct answer.

In option (e), the products in is wrong. Therefore, it is wrong.

In option (f), the concentration of is not included. Therefore, it is wrong.

The Acid dissociation constant expression (acidity constant expression) for the reaction:

 O a O b O c O d O e O f

The acid – dissociation constant is the ratio of the concentration of products and concentration of reactants . [] is neglected due to constant. Therefore, the final value should not contain concentration of water.