Question

What is the pH of \(0.01\ \mathrm{M}\) HCl?

• A. \(1\)
• B. \(2\)
• C. \(3\)
• D. \(12\)

Hint:

For a strong acid, \[ \boxed{ \mathrm{pH} = -\log[H^+]. } \] If \[ [H^+]=10^{-n}, \] then \[ \boxed{\mathrm{pH}=n.} \]

Answer 1

The Correct Option is B

Step 1: Determine the hydrogen ion concentration. HCl is a strong acid and dissociates completely. Therefore, \[ [H^+]=0.01=10^{-2}\ \mathrm{M}. \]

Step 2: Calculate the pH. The pH is given by \[ \boxed{ \mathrm{pH} = -\log[H^+]. } \] Substituting, \[ \mathrm{pH} = -\log(10^{-2}) = 2. \] Hence, \[ \boxed{\mathrm{pH}=2.} \] Therefore, \[ \boxed{(B)} \] is the correct answer.