Question

The number of water molecules in 1 litre of water is

• A. $18$
• B. $18\times {10}^3$
• C. $N_A$
• D. $55.55N_A$

Answer 1

Answer: (D)

$55.55N_A$

We know that density of water $1\frac{gm}{mL}$

Given volume of water $=1000$ mL

mass of water (given) $=1000\times 1=1000$ gm

$\therefore$ Moles $=\frac{1000}{18}=55.55$

$\therefore$ No. of molecules $=55.55$ $N_A$

Ans :- Option D.