Which of the following is a combination and which is a displacement reaction?

(a)

(b)

17 What type of chemical reactions are represented by the following equations?

(i) A + BCAC + B

(ii) A + B C

(iii) X Y + Z

(iv) PQ + RS PS + RQ

(v) A203 + 2B B203 + 2A

18 Balance the following chemical equations:

(a)

(b)

20 What type of reactions are represented by the following equations?

(a)

(b)

(c)

(d)

(e)

21 In the following reaction between lead sulphide and hydrogen peroxide :

(a) Which substance is reduced?

(b) Which substance is oxidised?