Question

Is carbonic acid formed during acid rain?

Answer 1

Carbonic acid is formed during acid rain.
Carbon dioxide reacts with water to form carbonic acid. Carbonic acid then dissociates to give the hydrogen ion (H+) and the hydrogen carbonate ion (HCO3-). The ability of H2CO3 to deliver H+ is what classifies this molecule as an acid, thus lowering the pH of a solution.
$CO2+H2O\to H2CO3$