The number of moles of H2O produced from 339 grams of SnO2

moles of H2O = 4.5 mol

Explanation:

balanced equation:

SnO2 + 2H2 → Sn + 2H20

∴ mass SnO2 = 339 g

∴ molar mass SnO2 = 150.71 g/mol

⇒ moles SnO2 = (339 g) (mol/150.71 g) = 2.25 mol SnO2

⇒ moles H2O = (2.25 mol SnO2) (2 mol H2O/mol SnO2)

⇒ moles H2O = 4.5 mol H2O