Question

The volume of water molecule is (Take, density of water is 103 kg m–3 and Avogadro’s number = 6 × 1023 mole–1)

• A. 3 × 10–28 m3
• B. 3 × 10–29 m3
• C. 1.5 × 10–28 m3
• D. 1.5 × 10–29 m3

Answer 1

Answer: (B)

3 × 10–29 m3

Answer 2

Molecular mass of water = 18

$\therefore$Number of molecular 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

$= \frac{Μass}{Density} = \frac{3 \times 10^{- 26}}{100} = \times 10^{- 29}m^{3}$

$= 3 \times 10^{- 29}m^{3}$