Give appropriate reason for each of the following :
Addition of chlorine to KI solution gives it a brown colour but excess of `Cl_(2)` makes it colourless.

Explanation

To understand why the addition of chlorine to a potassium iodide (KI) solution gives it a brown color, and why excess chlorine makes it colorless, we can break down the process into steps:

### Step 1: Addition of Chlorine to KI Solution
When chlorine gas (Cl₂) is added to a solution of potassium iodide (KI), a chemical reaction occurs. Chlorine acts as a strong oxidizing agent and oxidizes iodide ions (I⁻) present in KI to iodine (I₂).

**Chemical Reaction:**
\[
Cl_2 + 2KI \rightarrow 2KCl + I_2
...