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?
- nitrogen and carbondioxide
- the rare gases
- nitrogen and oxygen
-
nitrogen and the rare gases
- nitrogen, carbondioxide and the rare gases
The correct answer is: D
Explanation
- 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.