Zinc metal is added to dilute hydrochloric acid. The gas evolved is :
(a) Oxygen
(b) Hydrogen
(c) Chlorine
(d) Carbon dioxide

Q.

(a) Name the gas evolved when dilute hydrochloric acid is added to:
(i) Zinc metal
(ii) Calcium carbonate
(iii) Sodium sulphite
(iv) Lead (II) sulphide
(v) Magnesium bicarbonate
(vi) Potassium bisulphite
(b) Give a balanced equation for each of the above reaction.

Q. When zinc metal is heated with caustic soda solution, the gas evolved is :
(1) hydrogen
(2) carbon dioxide
(3) oxygen
(4) hydrogen choride

Q. When zinc reacts with dilute hydrochloric acid, the gas evolved is:

Q. Name the gas evolved when dilute hydrochloric acid reacts with sodium hydrogen carbonate. How is it recognised?
[2 Marks]

Q.

Question 33
Write a balanced chemical equation for each of the following reactions and also classify them.

(a) Lead acetate solution is treated with dilute hydrochloric acid to form lead chloride and acetic acid solution.

(b) A piece of sodium metal is added to absolute ethanol to form sodium ethoxide and hydrogen gas.

(c) Iron (III) oxide on heating with carbon monoxide gas reacts to form solid iron and liberates carbon dioxide gas.

(d) Hydrogen sulphide gas reacts with oxygen gas to form solid sulphur and liquid water.