10.8 g of aluminum reacted with water. how much hydrogen is released?

Given:

m (Al) = 10.8 g

Find:

V (H2) -?

Solution:

2Al + 3H2O = Al2O3 + 3H2, – we solve the problem, relying on the composed reaction equation:

1) Find the amount of aluminum that has reacted:

n (Al) = m: M = 10.8 g: 27 g / mol = 0.4 mol.

2) We compose a logical expression:

If 2 mol of Al gives 3 mol of H2,

then 0.4 mol Al will give x mol H2,

then x = 0.4 * 3: 2 = 0.6 mol.

3) Find the volume of hydrogen released during the reaction:

V (H2) = n * Vm = 0.6 mol * 22.4 L / mol = 13.44 L.

Answer: V (H2) = 13.44 liters.