`K_(a)` for butyric acid is `2.0xx10^(-5)`. Calculate pH and hydroxyl ion concentration in `0.2M` aqueous solution of sodium butyate.

Explanation

To solve the problem, we need to calculate the pH and hydroxyl ion concentration in a 0.2 M aqueous solution of sodium butyrate (NaC₄H₇O₂). Sodium butyrate is the sodium salt of butyric acid (HC₄H₇O₂), and it will dissociate in water to give butyrate ions (C₄H₇O₂⁻) and sodium ions (Na⁺). The butyrate ion can act as a weak base in water.

### Step-by-step Solution:

1. **Identify the Reaction:**
The butyrate ion (C₄H₇O₂⁻) can accept a proton (H⁺) from water, leading to the formation of butyric acid (HC₄H₇O₂) and hydroxide ions (OH⁻):
\[
C₄H₇O₂^- + H₂O \rightleftharpoons HC₄H₇O₂ + OH^-
...