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When air which contains the gases Oxygen, nitrogen, carbo...

When air which contains the gases Oxygen, nitrogen, carbondioxide, water vapour and the rare gases, is passed through alkaline pyrogallol and then over quicklime, the only gases left are?

A.

nitrogen and carbondioxide

B.

the rare gases

C.

nitrogen and oxygen

D.

nitrogen and the rare gases

E.

nitrogen, carbondioxide and the rare gases

Correct answer is D

- Alkaline solutions of pyrogallol absorb oxygen efficiently.

- Quicklime have a strong chemical affinity to absorb water.

- At room temperature, Calcium oxide (CaO) will spontaneously absorb carbon dioxide from the atmosphere.