Q. The number of water molecules in 1 L of water is
A) 18
B) $18 \times 1000$
C) $N_{A}$
D) 55.55 $N_{A}$
Explanation
(d)
For water, 1 g$= 1$ mL $(\because d$ for water = 1)
$\therefore 18\ g = 18$ mL
18 mL water $= 6.02 \times 10^{23}$ molecules $= N_{A}$ molecules
$\because$ in 100 mL number of water molecules $= \frac{N_{A} \times 1000}{18}$
$= 55.55N_{A}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.