In the reaction`3ClO^(-)(Aq)to ClO3^(-)`+2CI^(-)` The equivalent mass of `ClO^(-)` is :

Options

A. `M//4`
B. `M//3`
C. `3M`
D. `3M//4`

Explanation

To find the equivalent mass of \( \text{ClO}^- \) in the reaction

\[ 3 \text{ClO}^- \rightarrow \text{ClO}_3^- + 2 \text{Cl}^- \]

we will follow these steps:

### Step 1: Determine the oxidation states of chlorine in \( \text{ClO}^- \) and \( \text{ClO}_3^- \).

1. For \( \text{ClO}^- \):
- Let the oxidation state of Cl be \( x \).
- The oxidation state of O is \( -2 \).
- The overall charge of the ion is \( -1 \).
- Therefore, the equation becomes:
\[ x + (-2) = -1 \implies x - 2 = -1 \implies x = +1 \]
- So, the oxidation state of Cl in \( \text{ClO}^- \) is \( +1 \).

2. For \( \text{ClO}_3^- \):
- Let the oxidation state of Cl be \( x \).
- The oxidation state of O is \( -2 \).
- The overall charge of the ion is \( -1 \).
- Therefore, the equation becomes:
\[ x + 3(-2) = -1 \implies x - 6 = -1 \implies x = +5 \]
- So, the oxidation state of Cl in \( \text{ClO}_3^- \) is \( +5 \).

### Step 2: Calculate the change in oxidation state.

- The change in oxidation state of Cl from \( +1 \) to \( +5 \) is:
\[ 5 - 1 = 4 \]

### Step 3: Determine the equivalent weight of \( \text{ClO}^- \).

- The equivalent weight is calculated using the formula:
\[ \text{Equivalent weight} = \frac{\text{Molar mass}}{\text{Change in oxidation state}} \]
- Let the molar mass of \( \text{ClO}^- \) be \( M \).
- Since the change in oxidation state is \( 4 \), we have:
\[ \text{Equivalent weight} = \frac{M}{4} \]

### Step 4: Conclusion.

- The equivalent mass of \( \text{ClO}^- \) is \( \frac{M}{4} \).