How can you obtain hydrogen from a mixture of hydrogen and carbon monoxide.

When excess steam is mixed with the mixture of hydrogen and carbon monoxide, at elevated temperature of 450°C and using a catalyst iron [III] oxide, CO is converted to CO₂ with a further yield of hydrogen.

$\underset{\text{water gas}}{[\text{CO} + \text{H}$2 ]} + \underset{\text{excess steam}}{\text{H}2\text{O}} \underset{\text{Fe}2\text{O}3} {\xrightarrow{450 \degree \text{C}}} \text{ CO}2 + 2\text{H}2 + \Delta