Question

Sodium and water react according to the following equation. If 51.5 g of sodium are added to access water, how many liters of hydrogen gas are formed the STP ? Show all work.
2Na+2H2O—>2NaOH+H2

Answer 1

Answer is: volume is 25.08 liters.

Balanced chemical reaction: 2Na + 2H₂O → 2NaOH + H₂(g).

m(Na) = 51.5 g; mass of sodium.

n(Na) = m(Na) ÷ M(Na).

n(Na) = 51.5 g ÷ 23 g/mol.

n(Na) = 2.24 mol; amount of sodium.

From chemical reaction: n(Na) : n(H₂) = 2 : 1.

n(H₂) = 2.24 mol ÷ 2.

m(H₂) = 1.12 mol; amount of hydrogen gas.

V(H₂) = n(H₂) · Vm.

V(H₂) = 1.12 mol · 22.4 L/mol.

V(H₂) = 25.08 L; volume of hydrogen gas.