Understand that HCl is a strong acid, which means it dissociates completely in water. Therefore, the concentration of hydrogen ions [H⁺] is equal to the concentration of HCl.
Since the concentration of HCl is given as 0.0200 M, the concentration of hydrogen ions [H⁺] is also 0.0200 M.
Recall the formula for calculating pH: \( \text{pH} = -\log[\text{H}^+] \). This formula is used to find the pH from the concentration of hydrogen ions.
Substitute the concentration of hydrogen ions into the formula: \( \text{pH} = -\log(0.0200) \).
Use a calculator to find the logarithm and then multiply by -1 to determine the pH value.