Question

What is the mass of : $\left(a\right)$ $0.2$ mole of oxygen atoms? $\left(b\right)$ $0.5$ mole of water molecules?

Answer 1

(a) The mass of 1 mole of oxygen atoms = 16 g
Thus, the mass of 0.2 mole of oxygen atoms = 16 × 0.2 = 3.2 g

b) The mass of 1 mole of water molecules = 18 g
Thus, the mass of 0.5 mole of water molecules = 18 × 0.5 = 9.0 g