Page 219 - Chemistry ICSE Class IX

Chemistry Practicals 207

Chemical equation:
H S(g) + (CH COO) Pb(aq) o PbS(s) + 2CH COOH(aq)
2 3 2 3
lead acetate lead sulphide
(silvery black ppt.)
5. A colourless gas turns limewater milky and dil. KMnO solution colourless.
4
Ans. The gas is sulphur dioxide.
6. How will you find out if the given gas is hydrogen chloride or not?
Ans. If the gas gives the following tests, it will be hydrogen chloride gas.
x offensive odour
x turns moist blue litmus paper red.
x gives dense white fumes with ammonia.
7. Name a brownish gas which turns potassium iodide paper brown.
Ans. Nitrogen dioxide.
8. Name the gas which is greenish-yellow in colour. Give one more test shown by this gas.
Ans. Chlorine gas. This gas turns starch-iodide paper blue.
9. Name the reagents used for identifying the following gases:

(a) Hydrogen chloride (b) Sulphur dioxide (c) Nitrogen dioxide (d) Hydrogen sulphide
Ans. (a) Ammonia solution (b) KMnO solution (c) Potassium iodide (d) Lead acetate solution
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10. A colourless and odourless gas condenses to a colourless liquid. This liquid turns anhydrous copper sulphate blue. Name
the colourless, odourless gas.
Ans. Water vapour.
.
CuSO (s) + H O(l) o CuSO 5H O
4 2 4 2
white powder water blue colour
11. Both CO and SO turn limewater milky. Give a test to differentiate between the two.
2 2
Ans. CO is odourless, whereas SO has strong suffocating odour.
2 2