Calculate the hydronium ion and hydroxyl ion concentrations in
(1) 0.001 M HCI
(ii) 0.01 M NaOH
at 298 K assuming that both HCl and NaOH are completely ionised

Explanation

To solve the problem of calculating the hydronium ion (\( \text{H}_3\text{O}^+ \)) and hydroxyl ion (\( \text{OH}^- \)) concentrations for the given solutions of HCl and NaOH, we will follow these steps:

### Step 1: Calculate the hydronium ion concentration for 0.001 M HCl

1. **Identify the concentration of HCl**: The concentration of HCl is given as 0.001 M.
2. **Determine the ionization of HCl**: Since HCl is a strong acid, it completely ionizes in water:
\[
\text{HCl} \rightarrow \text{H}^+ + \text{Cl}^-
...