How much oxygen is needed to burn 11.2 liters of hydrogen?

The equation for the reaction of hydrogen with oxygen:

2H2 + O2 = 2H2O

The amount of hydrogen substance:

v (H2) = V (H2) / Vm = 11.2 / 22.4 = 0.5 (mol).

According to the reaction equation, 2 mol of H2 reacts with 1 mol of O2, therefore:

v (O2) = v (H2) / 2 = 0.5 / 2 = 0.25 (mol).

Thus, the required volume of oxygen, measured under normal conditions (n.o.):

V (O2) = v (O2) * Vm = 0.25 * 22.4 = 5.6 (l).

Answer: 5.6 l.