a) Define the following in term:. of electron transfer: (i) oxidation; (ii) reduction.

(b)(i) Determina the oxidation stale of phosphorus in each of the following structures: I. POCI\(_3\) II. PH\(_3\).

(ii) State with reasons whether the following compounds will form acidic, neutral or basic aqueous solutions: I. NaNO\(_3\) II. Na\(_2\)H\(_4\)CI; Ill. Na\(_2\)CO\(_3\).

(c) Consider the set-up

(i) What is the gas produced in the experiment illustrated by the set-up above?

(ii) Name the method of collection of gas

(iii) Give a reason for your answer in (c)(ii) above

(iv) State the function of the concentrated H\(_2\)SO\(_4\) in the conical flask

(v) Give of collection of the gas one I. physical property; II. chemical property of the gas

(vi) State one chemical test to identify the gas.

(d) A 4.3 g hydrated sodium tetraoxosulphate (VI) (Na\(_2\)SO\(_4\).xH\(_2\)O) was heated to remove the water of crystallization. The remaining anhydrous salt had a mass of 2.12 g. Calculate the value of x in the t I hydrated salt. [H = 1; O = 16; Na = 23; S = 32 ]