Which of the following acids is formed when carbon dioxide is dissolved in raindrops?

Carbonic acid

The correct answer is option 1. Carbonic acid

When carbon dioxide \((CO_2)\) dissolves in raindrops, it undergoes a chemical reaction with water \((H_2O)\) to form carbonic acid \((H_2CO_3)\). This process occurs in the atmosphere when carbon dioxide from the air dissolves in rainwater.

The chemical reaction is represented as follows:

\[ \text{CO}_2 + \text{H}_2\text{O} \rightarrow \text{H}_2\text{CO}_3 \]

In this reaction, carbon dioxide reacts with water to produce carbonic acid. Carbonic acid is a weak acid that dissociates in water to form bicarbonate ions (HCO3-) and hydronium ions (H3O+):

\[ \text{H}_2\text{CO}_3 \rightarrow \text{HCO}_3^- + \text{H}_3\text{O}^+ \]

The presence of carbonic acid in rainwater has important consequences for the weathering of rocks and minerals on the Earth's surface. Carbonic acid participates in chemical reactions that contribute to the breakdown of minerals and the erosion of geological formations over time. This process is a natural part of the carbon cycle and plays a role in shaping the Earth's landscape.