The Ka of hypochlorous acid (HC1O) is 3.0 × 10-8 at 25 °C. What is the percent ionization of hypochlorous acid in a 0.015M aqueous solution of HC1O at 25 °C?

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### Problem Statement

The \( K_a \) of hypochlorous acid (HClO) is \( 3.0 \times 10^{-8} \) at 25 °C. What is the percent ionization of hypochlorous acid in a 0.015 M aqueous solution of HClO at 25 °C?

### Explanation

This problem involves calculating the percent ionization of hypochlorous acid in a given solution. Percent ionization is a measure of the degree to which a weak acid ionizes in a solution. 

### Relevant Formula

To solve this problem, we use the following steps:

1. **Expression for the Equilibrium Constant (\(K_a\))**:
   $$ K_a = \frac{[H^+][ClO^-]}{[HClO]} $$

2. **Assumption for Weak Acid Ionization**: 
   Since \( HClO \) is a weak acid, we assume that \( x \) amount of \( HClO \) ionizes.
   $$ [H^+] = [ClO^-] = x $$
   $$ [HClO] = 0.015 - x \approx 0.015 \text{ M} \quad (\text{since } x \text{ is very small}) $$

3. **Substitute into the \( K_a \) Expression**:
   $$ K_a = \frac{x^2}{0.015} $$

4. **Solve for \( x \)**:
   $$ x = \sqrt{K_a \times 0.015} $$
   $$ x = \sqrt{(3.0 \times 10^{-8}) \times 0.015} $$
   $$ x \approx \sqrt{4.5 \times 10^{-10}} $$
   $$ x \approx 6.7 \times 10^{-5} \text{ M} $$

5. **Calculate Percent Ionization**:
   Percent Ionization = \( \frac{[\text{Ionized HClO}]}{[\text{Initial HClO}]} \times 100\% \)
   $$ \text{Percent Ionization} = \frac{6.7 \times 10^{-5}}{0.015} \times 100\% $$
   $$ \text{Percent Ionization} \approx 0
Transcribed Image Text:### Problem Statement The \( K_a \) of hypochlorous acid (HClO) is \( 3.0 \times 10^{-8} \) at 25 °C. What is the percent ionization of hypochlorous acid in a 0.015 M aqueous solution of HClO at 25 °C? ### Explanation This problem involves calculating the percent ionization of hypochlorous acid in a given solution. Percent ionization is a measure of the degree to which a weak acid ionizes in a solution. ### Relevant Formula To solve this problem, we use the following steps: 1. **Expression for the Equilibrium Constant (\(K_a\))**: $$ K_a = \frac{[H^+][ClO^-]}{[HClO]} $$ 2. **Assumption for Weak Acid Ionization**: Since \( HClO \) is a weak acid, we assume that \( x \) amount of \( HClO \) ionizes. $$ [H^+] = [ClO^-] = x $$ $$ [HClO] = 0.015 - x \approx 0.015 \text{ M} \quad (\text{since } x \text{ is very small}) $$ 3. **Substitute into the \( K_a \) Expression**: $$ K_a = \frac{x^2}{0.015} $$ 4. **Solve for \( x \)**: $$ x = \sqrt{K_a \times 0.015} $$ $$ x = \sqrt{(3.0 \times 10^{-8}) \times 0.015} $$ $$ x \approx \sqrt{4.5 \times 10^{-10}} $$ $$ x \approx 6.7 \times 10^{-5} \text{ M} $$ 5. **Calculate Percent Ionization**: Percent Ionization = \( \frac{[\text{Ionized HClO}]}{[\text{Initial HClO}]} \times 100\% \) $$ \text{Percent Ionization} = \frac{6.7 \times 10^{-5}}{0.015} \times 100\% $$ $$ \text{Percent Ionization} \approx 0
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