(a)(i) Define oxidation in terms of electron transfer.

(ii) Write balanced equations for the half reactions for the following changes in acidic solution: Mn0\(^-_4\) + Fe\(^{2+}\) —> Mn\(^{2+}\) + Fe\(^{3+}\)

(b)(i) Distinguish between an electrolytic celI and an electrochemical cell.

(ii) Sketch a cell for the electrolysis of molten magnesium chloride. Lable the anode and the cathode and indicate the direction of electron flow. Give the electrode reactions.

(iii) Give one reason why a platinum anode is not suitable for the eloctrolysis in (b)(i) above.

(c) Calculate the mass of lead that would be deposited from a solution of lead (II) trioxonitrate by the same quantity of electrically depositing 1.35g of copper. (Cu = 63.5, Pb = 207)

All your burette readings (initial and final) as well as the size size of your pipette, must be recorded but no account of experimental procedure is required. All calculations must be done in your answer book. 

Xg of pure potassium trioxocarbonate (IV) was treated with 1dm\(^3\) of 0. 25M tetraoxosulphate (VI) acid to obtain solution A which contains excess acid. B is a solution containing 2.8g of potassium hydroxIde per 250cm\(^3\) solution.

(a) Put A into the burette and titrate with 20cm\(^3\) or 25cm\(^3\) portions of B. using methyl orange as indicator. Record the volume of your pipette. Tabulate your burette readings and calculate the average volume of acid used.

(b) From your results and the information given. Calculate the;

(i) concentration of the excess acid in A in mol dm\(^3\)

(iii) value of X. The equation for the reaction between the excess acid the potassium hydroxide is H\(_2\)SO\(_4\) + 2KOH \(\to\) K\(_2\)SO\(_4\) [H = 1. C = 12, O = 16. S = 32, K = 39]

Credit will be given for strict adherence to the instructions, for observations precisely recorded, and for accurate inferences. All tests, Observations, and inferences must be clearly entered in your answer book, in ink, at the time they are made. Carry out the following exercises on sample C.

Record your observations and identify any gases evolved 

(a) Put all of C into a test tube and add about 5cm\(^3\) of water. Shake the mixture and filter. Keep both the residue and the filtrate

(b) Divide the filtrate into two portions;

(i)  To the first portion, add a few drops of dilute trioxonitrate (V) acid followed by about 1cm\(^3\) of silver trioxonitrate (V) solution 

(ii) Add excess aqueous ammonia to the mixture in (i) above

(iii) To the second portion, add about 2cm\(^3\) of dilute sodium hydroxide solution and warm gently

(c) Add about 2cm\(^3\) of dilute hydrochloric acid to the residue from (a) above and warm gently. Filter if necessary and divide the resulting solutio into two portions.

(i) To the first portion add dilute sodium hydroxide solution in drops until it is in excess

(ii) To the second portion, add aqueus ammonia in drops until it is in excess.

(a)(i) Give one laboratory use of activated charcoal

(ii) A piece of phosphorus and some magnesium ribbon were burnt in two separate jars of oxygen. Water was then added to dissolve the product. State the action of litmus on each of the resulting solutions

(b) Give one chemical test to distinguish between CH\(_3\)CH\(_2\)OH and CH\(_3\)COOH.

(c) Describe how you would dilute accurately a solution containing 0.10 mole of the solute per dm\(^3\) of solution to 0.010M.