When `Cl_(2)` water is added to an aqueous solution of potassium halide in presence of chloroform, a violet colour is obtained upon shaking. This confirms the presence of

Options

A. iodide
B. bromide
C. chloride
D. iodide and bromide

Explanation

To solve the question, we need to analyze the reaction between chlorine water (Cl2 in water) and potassium halides in the presence of chloroform. Here's a step-by-step breakdown of the solution:

### Step 1: Identify the Reaction
When chlorine water is added to an aqueous solution of potassium halide (KX), we need to identify which potassium halide can react with chlorine. The common potassium halides are potassium iodide (KI), potassium bromide (KBr), and potassium chloride (KCl).

### Step 2: Consider the Reactivity
Chlorine (Cl2) is a strong oxidizing agent and can react with halide ions. Among the potassium halides, potassium iodide (KI) is the most likely candidate because iodine (I2) can be formed from iodide ions (I-) when they react with chlorine.

### Step 3: Write the Reaction
The reaction between potassium iodide and chlorine can be written as:
\[ 2 KI + Cl_2 \rightarrow 2 KCl + I_2 \]
In this reaction, potassium iodide (KI) is oxidized to potassium chloride (KCl), and iodine (I2) is produced.

### Step 4: Color Change Observation
Iodine (I2) is known to have a brown color in solution. When iodine is dissolved in chloroform (CHCl3), it imparts a violet color to the chloroform layer. This is due to the solubility of iodine in chloroform, which is a non-polar solvent.

### Step 5: Conclusion
The violet color observed upon shaking indicates the presence of iodine (I2) in the solution, confirming that iodide ions (I-) were present in the original potassium halide solution.

### Final Answer
The presence of iodide ions is confirmed by the violet color obtained upon shaking.

**Answer: Iodide ions (I-)**

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