Question

The pOH of 0.01 M HCl solution is ________.

• A. 1
• B. 2
• C. 11
• D. 12

Hint:

Don't confuse pH and pOH. For acids, first find the pH from $[H^+]$, then subtract from 14 to get pOH.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
\(HCl\) is a strong acid that dissociates completely in water. The concentration of \(H^+\) ions is equal to the molarity of the acid.
Step 2: Key Formula or Approach:
\[ pH = -\log[H^+] \]
\[ pH + pOH = 14 \text{ (at } 298 \text{ K)} \]
Step 3: Detailed Explanation:
Given: \([HCl] = 0.01 \text{ M} = 10^{-2} \text{ M}\)
Since it's a strong acid, \([H^+] = 10^{-2} \text{ M}\)
Calculate \(pH\):
\[ pH = -\log(10^{-2}) = 2 \]
Calculate \(pOH\):
\[ pOH = 14 - pH \]
\[ pOH = 14 - 2 = 12 \]
Step 4: Final Answer:
The \(pOH\) of the solution is \(12\).