. Read the following and answer any four questions from (i) to (v) In the below experiment, when an iron nail is dipped in copper sulphate solution, a brown coating of copper is formed in the surface of iron and the colour of copper sulphate solution changes from blue to pale green. The reaction shows that iron is more reactive than copper because it displaces copper from the copper sulphate solution.

(i) The equation Cu + xHNO3 →
Cu(NO3)2 + yNO2 + 2H2O.
The values of x and y are
(a) 3 and 5
(b) (b) 8 and 6
(c) (c) 4 and 2
(d) (d) 7 and 1

(ii) What happens when copper rod is
dipped in iron sulphate solution :
(a) Copper displaces iron
(b) Blue colour of copper sulphate solution
is obtained
(c) No reaction takes place
(d) Reaction is exothermic

(iii) A substance which oxidised itself
and reduces other is known as :
(a) Oxidising agent
(b) (b) Reducing agent
(c) (c) Both (a) and (b)
(d) (d) None of these