(a) Mention one oxide in each case, which

(i) used in bleaching

(ii) is a redish-brown gas

(iii) reacts with NaOH and also with HCI;

(iv) dissolves in water to give a solution with pH greater than 7;

(v) oxidizes hot, concentrated HCI to chlorine

 

(b)(i) State three methods that can be used to removo hardness in a sample of water that contains calcium hydrogentrioxocarbonate (IV).

(ii) Explain with the aid of appropriate equation, why it is not advisable to build a house with limestone in an environment polluted by sulphur (IV) oxide.

 

(c)(i) List two compounds of potassium which yield oxygen when heated strongly

(ii) Calculate the amount (in moles) of gas which occupies 250 cm\(^3\) at s.t.p. [1 mole of gas occupies 22.4 dm\(^3\) at s.t.p]

(iii) If 250 cm\(^3\) of a gas at s.t.p. is heated to 27°C at constant pressure, calculate its new volume.

(iv) Explain in terms of the collision theory what happens as a gas is heated at constant pressure.