Q. The pH of the solution 5 mL $\frac{M}{5}\ HCl + 10\ mL\ of\ \frac{M}{10}\ NaOH$ is
A) 5
B) 3
C) 7
D) 8
Explanation
(c)
Given, vol. of $HCl = 5\ mL,\ molarity =$M/5
Vol. of $NaOH = 10\ mL,\ molarity =$M/10
Mulliequivalents of $HCl = 5 \times \frac{1}{5} = 1$
Mulliequivalents of $NaOH = 10 \times \frac{1}{10} = 1$
$HCl + NaOH \rightarrow NaCl + H_{2}O$
$\because$ Mulliequivalents of $HCl$ = Mulliequivalents of $NaOH$
$\therefore$ Solution is neutral and pH=7.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.