Question

A sample of air is slowly passed through aqueous Sodium hydroxide and then over heater copper.

Which gases are removed by this process?
a) Carbon dioxide and water vapour
b) Carbon dioxide and oxygen
c) Nitrogen and oxygen
d) Nitrogen and water vapour

Answer 1

A sample of air is slowly passed through aqueous Sodium hydroxide and then over heater copper Carbon dioxide and oxygen.

Answer 2

Answer:

Option b) Carbon dioxide and oxygen

Explanation:

Thinking process:

Sodium hydroxide is an alkaline solid substance. It reacts with acids to form salts and water. In this case, it is known that carbon dioxide, CO₂, is an acidic gas. Therefore, the reaction gives a salt that results in carbon dioxide being absorbed by the sodium hydroxide.

Heated copper is an excellent removal of oxygen. This is because monovalent copper, Cu, has a deep binding affinity for oxygen.  Hence the the oxygen trapped by the atom.