Question

Calculate the mass of
(i) 10²² atoms of sulphur,
(ii) 0.1 mole of carbon dioxide.

[Atomic mass: S = 32, C = 12 and O = 16 and Avogadro's Number = 6 × 10²³]

Answer 1

(i) Number of moles in 10²² atoms of sulphur atoms = $\frac{{10}^{22}}{6.022\times {10}^{23}}=0.0166$ moles
Mass of 1 mole of sulphur atoms = 32 g
Mass of 0.0166 mole of sulphur atoms = (32 $\times$ 0.0166) = 0.5312 g

(ii) Mass of 1 mole of carbon dioxide molecules = 44 g
Mass of 0.1 mole of carbon dioxide molecules = (44 $\times$ 0.1) = 4.4 g