Mole Concept and Stoichiometry — Question 28

Molecular wt. of any substance contain 6.022 × 10²³ molecules.

Mass of 1 mole of water is 2H + O = 2 + 16 = 18 g

18 g of H₂O contains 6.022 × 10²³ molecules

∴ 0.09 g of H₂O contains $\dfrac{6.022 \times 10^{23} \times 0.09 }{18}$

= 3.01 × 10²¹ molecules