Explain the methods opted for the separation of gas-gas mixture
Answers
Answer:
The methods involved are:
1. Diffusion
2. Solubility in solvent (Solvent extraction)
3. Liquefaction
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Diffusion :
The mixture of two gases is passed through a porous partition. Lighter gases diffuse more rapidly compared to heavier gases. Vapour density of ammonia gas is 8.5 and that of hydrogen chloride is 18.25. Ammonia gas is lighter; hence, it is diffused first. The heavier gas hydrogen chloride is diffused later.
Similarly, a mixture of gases like hydrogen (vapour density 1) and oxygen (vapour density 16) is separated by this method, because hydrogen is lighter, diffuses first.
Solubility in solvent:
The mixture of gases is passed through a solvent such as water. The insoluble gas oxygen gas (4 vols.) gets bubbled out from the solvent. Hydrogen gas (450 vols.) is soluble in water and can be expelled by boiling.
Liquefaction:
Mixture of two gases is passed through a flask placed in a freezing mixture. The easily liquefiable component Chlorine gas (15°C – 5.7 atmos.) solidifies in the freezing mixture. The gas which is difficult to liquefy Oxygen (-183°C – 10 atmos.) bubbles out from the freezing mixture. The solidified component is recovered from the freezing mixture by warming.
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Hope it helps :)