`K_(1)` and `K_(2)` for dissociation of `H_(2)A` are `4xx10^(-3)` and `1xx10^(-5)`. Calculate concentration of `A^(2-)` ion in `0.1M H_(2)A` solution. Also report `[H^(+)]` and pH.

Explanation

To solve the problem, we need to calculate the concentration of the \( A^{2-} \) ion in a \( 0.1 \, M \) solution of \( H_2A \), given the dissociation constants \( K_1 \) and \( K_2 \).

### Step 1: Write the dissociation equations

1. The first dissociation of \( H_2A \):
\[ H_2A \rightleftharpoons H^+ + HA^- \]
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