The boiling points of oxygen and argon are –183 °C and –189 °C, respectively. Because the boiling points are so similar, argon obtained from the fractional distillation of liquid air is contaminated with oxygen. The following three-step procedure can be used to obtain pure argon from the oxygen-contaminated sample:

(1) Excess hydrogen is added to the mixture and then the mixture is ignited.

(2) The mixture from step (1) is then passed over hot copper(II) oxide.

(3) The mixture from step (2) is passed over a dehydrated zeolite material.

Explain the purpose of each step, writing chemical equations for any reactions that occur.