1. Zinc reacts with steam according to the equation:

Zn) + H2O → ZnO + H2

What mass of zinc oxide is formed from 41.6g of zinc?

+ H2 (g)

2. Sulfur burns in air to form sulfur dioxide according to the equation:

S (s) +

O2 (g)

→ SO2 (g)

What volume of sulfur dioxide is produced (at room temperature

24 of sulfur?

1) mass ZnO = 55.155 g

2) V SO2 (g) = 18.289 L

Explanation:

1) Zn + H2O → ZnO + H2

∴ mass Zn = 41.6 g

∴ mm Zn = 65.38 g/mol

⇒ mol Zn = (41.6 g) (mol/61.38 g) = 0.678 mol Zn

⇒ mol ZnO = (0.678 mol Zn) (mol ZnO/mol Zn) = 0.678 mol ZnO

∴ mm ZnO = 81.38 g/mol

⇒ mass ZnO = (0.678 mol ZnO) (81.38 g/mol) = 55.155 g ZnO

2) S (s) + O2 (g) → SO2 (g)

∴ mass S (s) = 24 g

∴ T = 25°C ≅ 298 K

∴ P = 1 atm

∴ mm S (s) = 32.065 g/mol

⇒ mol S (s) = (24 g) (mol/32.065 g) = 0.7485 mol S (s)

⇒ mol SO2 (g) = (0.7485 mol S (s)) (mol SO2 (g) / mol S (s)) = 0.7485 mol SO2 (g)

ideal gas:

PV = RTn

⇒ V SO2 (g) = ((0.082 atm. L/K. mol) (298 K) (0.7485 mol)) / (1 atm)

⇒ V SO2 (g) = 18.289 L SO2 (g)