$150 mL$ of $0.2 M$ $HCl$ is mixed with $100 mL$ of $0.1 M$ $NaOH$ at 298 K. Find the pH of the mixture to two decimals (use $lo g 2 = 0.301$ ).

Numerical answer type, tolerance 0.01.

Answer: 1.1

Moles of

H X^{+} = 30 mmol

, of

OH X^{-} = 10 mmol

, excess

H X^{+} = 20 mmol

250 mL

, so

[H X^{+}] = 0.08 M

and

pH = 1.097 \approx 1.10