1.A solution of a substance 'X' is used for whitewashing.
(i) Name the substance X' and write its formula.
(ii) Write the reaction of the substance X named in (1) above with
water.
2.why is the amount of gas collected in one of the test tubes in Activity
1.7 double of the amount collected in the other? Name this gas.
Answers
Answer:
1)
(i) The substance ‘X’ is calcium oxide. Its chemical formula is CaO.
(ii) Calcium oxide reacts vigorously with water to form calcium hydroxide (slaked lime).
CaO (s)+ H2O (l) → Ca(OH)2 (aq)
Calcium Oxide (Quick Lime) + Water → Calcium Hydroxide (Slaked Lime).
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2) water contain two parts hydrogen and one part of oxygen. therefore the amount of hydrogen and oxygen produced during electrolysis of water 2 : 1 during electrolysis is hydrogen goes to one test tube and goes to another amount of gas collected is one of test tube is double of the amount collected in others.
Answer:
i) Calcium oxide or quick lime or CaO is the substance.
ii) CaO(s)+ H2O(l)= Ca(OH)2(aq)
Explanation:
Because water is made up of Hydrogen gas and Oxygen gas combined in ratio 2:1 . Amount of Hydrogen gas collected at Cathode is double the amount of Oxygen collected at Anode.