Question

A student preparing for the experiments inadvertently adds an additional 400 mL of the same acid solution to 500 mL of 0.1 M HCl.

What will be the new pOH of this solution?

A) 1.0 B) 6.0 C) 11.0 D) 13.0

Answer 1

The pOH of this solution will be 13 (option D)

Step-by-step explanation:

Step 1: Data given

pH + pOH = 14

pH = -log [H+]

[H] = [HCl]

An acid solution has a pOH greater than 7 (this eliminates option A and B)

Step 2: Calculate ph and pOH

Since the concentration remains the same, then volume changes will not affect pH.

The pH of a solution with strong acid is given as:

pH= -log[H+].

Since the concentration of HCl = 0.1 M = [H+]

pH = -log (0.1)

pH = 1

pOH = 14 - pH

pOH = 14 - 1

pOH = 13

The pOH of this solution will be 13 (option D)