Question

What is the pH of a 0.01 M solution of hydrochloric acid (HCl)?

• A. \( 1 \)
• B. \( 2 \)
• C. \( 4 \)
• D. \( 3 \)

Hint:

For strong acids, the concentration of \( \text{H}^+ \) ions is equal to the concentration of the acid in solution.

Answer 1

The Correct Option is B

The pH of a strong acid, such as HCl, is determined by the formula: \[ \text{pH} = -\log[\text{H}^+] \] For HCl, the concentration of \( \text{H}^+ \) ions equals the molar concentration of HCl, given as \( 0.01 \, \text{M} \). By substitution: \[ \text{pH} = -\log(0.01) = -(-2) = 2 \] Consequently, the solution's pH is 2.