Question

When a large amount of carbon dioxide dissolves in a water body, the water becomes acidic because of the formation of which of the following acids?

• A. Carboxylic acid
• B. Carbamic acid
• C. Carbolic acid
• D. Carbonic acid

Answer 1

Answer:

D. Carbonic acid

Carbonic Acid Formation in Water Bodies

When carbon dioxide (CO2) gas dissolves in water (H2O), a chemical reaction occurs, leading to the formation of carbonic acid (H2CO3).

Chemical Reaction:

• The reversible reaction can be represented as: CO2 + H2O <=> H2CO3

• This process is crucial in natural systems, including oceans, lakes, and rivers.

Acidic Nature:

• Carbonic acid is a weak acid.

• Upon dissolving in water, it dissociates partially to release hydrogen ions (H+) and bicarbonate ions (HCO3-), and further to carbonate ions (CO3^2-) and more H+ ions.

• The increase in hydrogen ion concentration lowers the pH of the water, making it more acidic.