(a) What is the activity series of metals ? Arrange the metals Zn, Mg, Al, Cu and Fe in a decreasing order of reactivity. (b) What would you observe when you put (i) some zinc pieces into blue copper sulphate solution ? (ii) some copper pieces into green ferrous sulphate solution ? (c ) Name a metal which combines with hydrogen gas. Name the compound formed.

(a) What is the activity series of metals ? Arrange the metals Zn, Mg,

1.	(a) What is the activity series of metals ? Arrange the metals Zn, Mg, Al, Cu and Fe in a decreasing order of reactivity. (b) What would you observe when you put (i) some zinc pieces into blue copper sulphate solution ? (ii) some copper pieces into green ferrous sulphate solution ? (c ) Name a metal which combines with hydrogen gas. Name the compound formed.
Answer» Solution :(a) (i) Blue colour of copper SULPHATE solution would slowly disappear. (ii) No CHANGE would be noticed. (c ) Sodium combines with hydrogen to form sodium hydride. `2Na + H_(2)rarr UNDERSET("SOD. hydride")(2NaH)`