Question

The volume of water molecule is
(Take, density of water is $10^{3}kg{m}^{-3}$ and avogadro’s number $=6\times 10^{23}$ mole${}^{-1}$)

• A. $3\times 10^{-28}{m}^3$
• B. $3\times 10^{-29}{m}^3$
• C. $1.5\times 10^{-28}{m}^3$
• D. $1.5\times 10^{-29}{m}^3$

Answer 1

Answer: (B)

Molecular mass of water $=18$
$\therefore$ Number of molecules in $18g$
or$0.018kg$ of water $=6\times 10^{23}$
$\therefore$ Mass of molecule of water $=\frac{0.018}{6\times 10^{23}}=3\times 10^{-26}$
$\therefore$ Volume of a water molecule
$=\frac{Mass}{Density}=\frac{3\times 10^{-26}}{1000}=3\times 10^{-29}{m}^3$