The colour of the solution obtained by adding excess of Kl in the solution of `HgCl_2` is

Options

A. orange
B. brown
C. red
D. colourless

Answer

To determine the color of the solution obtained by adding excess KI (potassium iodide) to a solution of HgCl2 (mercuric chloride), we can follow these steps:

### Step 1: Identify the Reactants
We start with a solution of HgCl2, which is a colorless solution. When we add excess KI to this solution, we are introducing iodide ions (I⁻) into the system.

**Hint:** Look for the chemical reactions that occur when iodide ions are introduced to mercuric chloride.

### Step 2: Write the Reaction
When excess KI is added to HgCl2, a chemical reaction occurs where mercuric iodide (HgI2) is formed along with potassium chloride (KCl). The reaction can be represented as follows:

\[ \text{HgCl}_2 + 2 \text{KI} \rightarrow \text{HgI}_2 + 2 \text{KCl} \]

**Hint:** Identify the products formed in the reaction and their states.

### Step 3: Identify the Product
The product formed, HgI2 (mercuric iodide), is known to have a specific color. In this case, mercuric iodide can appear as a precipitate.

**Hint:** Research the properties of mercuric iodide to determine its color.

### Step 4: Determine the Color of the Precipitate
Mercuric iodide (HgI2) is known to form a scarlet red precipitate when it is produced in the reaction. Therefore, the solution will exhibit a red color due to the formation of this precipitate.

**Hint:** Consider the visual characteristics of precipitates formed in chemical reactions.

### Final Answer
The color of the solution obtained by adding excess KI to the solution of HgCl2 is scarlet red due to the formation of mercuric iodide (HgI2).

### Summary
1. Start with a colorless solution of HgCl2.
2. Add excess KI to form HgI2 and KCl.
3. HgI2 precipitates as a scarlet red solid.
4. Therefore, the solution will appear scarlet red.