(a)(i) List two uses of aluminium and state how each use is related to the properties of the element.

(ii) State the reason why aluminium oxide is said to be amphoteric.

(b) Calcium is extracted by the electrolysis of fused calcium chloride containing about one-sixth of its mass of calcium fluoride.

(i) Sketch and label the cell used for the extraction.

(ii) Write equations for the reactions at the electrodes.

(iii) State the role of the calcium fluoride in the extraction.

(c) W, X, Y and Z represent four metals which have the following properties: W does not react with cold water but it liberates hydrogen from steam; X is one of the products formed when its trioxonitrate (V) decomposes on strong heating; Z forms the oxide when heated in air and it displaces W from an aqueous solutions of a salt of W; Y tarnishes rapidly exposure and reacts vigorously with cold water. Use the information provided to deduce the order of reactivity of the metals.

(a)(i) Define a standard solution

(ii) Give the reason why a standard solution of sodium hydroxide cannot be made by weighing out accurately a given mass of the solid and making it up to the required volume of solution

(b) Give two ways by which a solid solute can be made to dissolve more quickly in a liquid Solvent

(i) Draw a labelled diagram of the apparatus used for drying solids in the laboratory

(c) State what would be observed if a fresh precipitate of silver chloride was;

(i) Exposed to light.

(ii) Shaken will excess aqueous ammonia

Credit will be given for strict adherence to 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.

 H is a mixture of an element and an organic compound. Carry out the following exercises on H. Record your observations and identify any gases evolved. State the conclusion you draw from the result of each test

(a) Put all of H in a beaker and add about 10cm\(^3\) of distilled water. Stir the mixture thoroughly and filter  Keep both the filtrate and the residue. Test the filtrate with litmus paper.

(b) Divide the filtrate into two portions

(i) To the first portion add two to three drops of acidified potassium tetraoxomanganate (VII) and warm

(ii) To the second portion. add a few drops of a saturated solution of sodium hydrogentrioxocarbonate (IV)

(c)(i) Put all the residue in a test tube and add 5cm\(^3\) of dilute hydrochloric acid

(ii) To the resulting solution from (C)(i) above add aqueous sodium hydroxide in drops until it is in excess

(iii) From your inferences in (c)(i) and (c)(i) state what would be observed if 5cm\(^3\) of dilute trioxonitrate (V) acid were added to a portion of the residue and the mixture was warmed. 

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

F is a solution, O a dibasic acid H\(_2\)X. G is a solution containing 1.00g of sodium hydroxide in 250cm\(^3\) of solution.

(a) Put F in the burette and titrate with 20cm\(^3\) or 25cm\(^3\) portion of G using methyl orange as indicator. Record the volume of your pipette. Tabulate your burette readings and calculate the average volume of F used 

(b) From your results and the information provided, calculate the;

(i) concentration of G in mol. dm\(^3\)

(ii) concentration of F in mol. dm\(^{-3}\)

(iii) molar mass of the acid H\(_2\)X, given that 100cm\(^3\) of solution F contained 0.4850 the acid.

The equation for the reaction is H\(_2\)X\(_{(aq)}\) + 2NaOH\(_{(aq)}\) \(\to\) Na\(_2\)X\(_{(aq)}\) + 2H\(_2\)O [H = 1; O = 16; Na = 23]