Write the balanced equation for each reaction. Phases are optional.

(1) The carbonate ion (CO2-3) acts as a Brønsted base with water.

(2) The carbon-containing product from the first reaction acts as a Brønsted base with water.

(3) The carbon-containing product from the second reaction decomposes into carbon dioxide gas and water.

Consider the products of the reactions. When the carbonate ion reacts with water, is the resulting solution acidic or basic?

1. CO₃⁻² + H₂O ⇄ HCO₃⁻ + OH⁻

2. HCO₃⁻ + H₂O ⇄ H₂CO₃ + OH⁻

3. H₂CO₃ → H₂O + CO₂

Basic solution

Explanation:

Brønsted Lowry theory:

Acid → Release a proton

Base → Accept a proton

1. CO₃⁻² + H₂O ⇄ HCO₃⁻ + OH⁻

Carbonate takes a proton from the water

2. HCO₃⁻ + H₂O ⇄ H₂CO₃ + OH⁻

Bicarbonate takesa proton from the water to produce carbonic acid.

3. H₂CO₃ → H₂O + CO₂

Carbonate acid decomposes into CO₂ and H₂O

In the first reaction, when the carbonate takes a proton from the water, water releases OH⁻, so the solution is basic.