Give reason for each of the following:
 Concentrated nitric acid turns yellowish brown when exposed to sunlight 

Explanation

To explain why concentrated nitric acid (HNO₃) turns yellowish brown when exposed to sunlight, we can break down the process into clear steps:

### Step 1: Decomposition of Nitric Acid
When concentrated nitric acid is exposed to sunlight, it undergoes a decomposition reaction. The chemical reaction can be represented as follows:

\[ 4 \text{HNO}_3 \rightarrow 4 \text{NO}_2 + 2 \text{H}_2\text{O} + \text{O}_2 \]
...