It is given that `0.001 mol` each of `Cd^(2+)` and `Fe^(2+)` ions are contained in `1.0L` of `0.02M HC1` solution. This solutions is now saturated with `H_(2)S` gas at `25^(@)C`.
a. Determine whether or not each of these ions will be precipitated as sulphide?
b. How much `Cd^(2+)` ions remains in the solution at equilibrium?
`K_(1)(H_(2)S) = 1.0 xx 10^(-7), K_(2) (H_(2)S) = 1.0 xx 10^(-14)`: ltbRgt `K_(sp) (CdS) = 8 xx 10^(-27): K_(sp) (FeS) = 3.7 xx 10^(-19)`.

Explanation

To solve the problem step by step, we will address both parts (a) and (b) of the question.

### Part (a): Determine whether or not each of these ions will be precipitated as sulphide.

1. **Identify the concentrations of ions:**
- We have `0.001 mol` of `Cd^(2+)` and `Fe^(2+)` in `1 L` of solution, so:
- \[ [Cd^{2+}] = 0.001 \, \text{M} \]
- \[ [Fe^{2+}] = 0.001 \, \text{M} \]
...