Final answer:
The pH of an HCl solution with a hydronium ion concentration of 0.001 M is 3, and the corresponding pOH is 11.
Step-by-step explanation:
The pH and pOH of a solution can be calculated using the concentrations of hydronium ions [H3O+] and hydroxide ions [OH-]. For a solution of HCl with a H3O+ concentration of 0.001 M, the pH is calculated using the formula:
pH = -log[H3O+]
Inputting the given concentration:
pH = -log(0.001) = 3
Since HCl is a strong acid we assume it dissociates completely, so the pOH can be determined by the relationship:
pOH = 14 - pH
Therefore:
pOH = 14 - 3 = 11