When `O_(3)` is passed through an aqueous solution of KI, the pH of the resulting solution is

Options

A. 7
B. 6.8
C. 2.8
D. 4.2

Answer

To determine the pH of the solution when ozone (O₃) is passed through an aqueous solution of potassium iodide (KI), we can follow these steps:

### Step 1: Identify the Reaction
When ozone is introduced into an aqueous solution of KI, it reacts with potassium iodide. The reaction can be represented as:
\[ 3 O_3 + 2 KI + 3 H_2O \rightarrow 3 O_2 + I_2 + 2 KOH \]

### Step 2: Analyze the Products
From the reaction, we can see that the products include:
- Oxygen gas (O₂)
- Iodine (I₂)
- Potassium hydroxide (KOH)

### Step 3: Determine the Nature of the Solution
Potassium hydroxide (KOH) is a strong base. However, the presence of iodine (I₂) is also significant. Iodine in solution can lead to the formation of iodide ions (I⁻) and can also affect the acidity of the solution.

### Step 4: Assess the Oxidation State Changes
In this reaction, the oxidation state of iodine changes from -1 in KI to 0 in I₂, indicating that oxidation has occurred. The formation of I₂ from KI indicates that the solution will have a certain acidity due to the presence of iodine.

### Step 5: Determine the pH
The presence of I₂ in the solution gives it a reddish color, which is indicative of an acidic environment. The pH of the resulting solution will be less than 7.

### Conclusion
Based on the reaction and the products formed, we can conclude that the pH of the resulting solution when O₃ is passed through an aqueous solution of KI will be approximately between 6 to 7, indicating that it is slightly acidic.

### Final Answer
The pH of the resulting solution is approximately 6 to 7.

---