Calculate the `pH` of `0.02` M `H_2S` (aq) given that
`K_(a_1)=1.3xx10^(-7), K_(a_2)=7.1xx10^(-15)`

Explanation

To calculate the pH of a 0.02 M solution of H₂S, we need to consider the dissociation of H₂S in water and the given acid dissociation constants (Kₐ).

### Step-by-Step Solution:

1. **Identify the Dissociation Reactions**:
H₂S dissociates in two steps:
- First dissociation:
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