collection and drying of gases 💨

Question 1

which gases are soluble in water?

Answer 1

chlorine, ammonia, sulfur dioxide, hydrogen chloride, carbon dioxide (slightly)

Question 2

which gases are insoluble in water?

Answer 2

oxygen, hydrogen, nitrogen, carbon monoxide

Question 3

which gases are acidic?

Answer 3

carbon dioxide, chlorine, hydrogen chloride, nitrogen dioxide, sulfur di/trioxide

Question 4

which gases are neutral?

Answer 4

oxygen, hydrogen, nitrogen, carbon monoxide

Question 5

which gases are alkaline?

Answer 5

ammonia

Question 6

what are the methods for collection of gas?

Answer 6

1) displacement of water: insoluble gases
2) displacement of air (depending on Mr of gas compared to air, 29.0)
3) using a graduated gas syringe, volume measured at rtp

Question 7

what are the methods for drying of gas?

Answer 7

1) concentrated sulfuric acid (acid and neutral gas)
2) fused calcium chloride (acid and neutral gas)
3) calcium oxide (alkaline gas)

Question 8

solubility table

Answer 8

• all group 1 metal and ammonia salts: soluble
• all nitrates: soluble
• all chlorides: soluble except Ag and Pb
• all sulfates: soluble except Ag, Pb, Ba and Ca
• all carbonates: insoluble except group 1 and ammonia
• all hydroxides: insoluble except group 1 and ammonia

Question 9

what are the separation techniques?

Answer 9

1) filtration
2) evaporation to dryness
3) crystallisation
4) simple + fractional distillation
5) sublimation
6) using a separating funnel
7) paper chromatography