Question

What is the pH of a 0.01 M solution of HCl?

• A. 1
• B. 2
• C. 3
• D. 4

Hint:

For strong acids, pH is simply the negative logarithm of the molar concentration. Ensure the concentration is in the correct units (moles per liter).

Answer 1

The Correct Option is B

Step 1: Acknowledge that HCl is a strong acid and fully dissociates in water: \[ \text{HCl} \rightarrow \text{H}^+ + \text{Cl}^-. \] Consequently, the concentration of H\(^+\) ions is equivalent to the HCl concentration, which is 0.01 M.
Step 2: Compute the pH using the formula \( \text{pH} = -\log_{10}[\text{H}^+] \). Input the H\(^+\) concentration: \[ \text{pH} = -\log_{10}(0.01) = -\log_{10}(10^{-2}) = -(-2) = 2. \]
Step 3: Confirm the outcome. A pH of 2 is expected for a 0.01 M solution of a strong acid, aligning with the calculation.