Q. Volume of water needed to mix with 10 mL N HCl to get 0.1 N HCl is
A) 900 mL
B) 9 mL
C) 90 mL
D) 100 mL
Explanation
(c)
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ N_{1}V_{1}\ \ = {\ \ \ N}_{2}V_{2}$
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 10\ \times \ 1 = \ 0.1 \times \ V_{2}\ \ \$
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ V_{2} = \ \frac{10}{0.1}\ \ \$
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ V_{2} = 100mL$
Hence, water needed to mix
= 100-10=90 mL
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.