(a) Name the apparatus used in the laboratory to (i) Convert vapour into liquid during distillation

(ii) determine the volumetric composition of water

(ii) produce an intermittent supply of any gas which can be evolved by the action of a liquid on a solid without heating.

(b) Give the reason for the following;

(i) the edge of the lid of a desiccator should be greased

(ii) a standard solution of sodium hydroxide is not prepared by weighing out accurately a given mass of the solid and making it up to the required volume.

iii) after the reduction of copper (II) oxide by a a stream of hydrogen gas passed overs the heated oxide in a combustion tube, it is necessary to continue passing the gas over the residue until the residue cools.

(c) An acid-base indicator turns orange in an acidic solution, green in a neutral solution and blue in an alkaline solution. The table shows the results obtained when a few drops of the indicator were added to samples of some liquids.

(i) Arrange the liquids in increasing order of their expected pH values.

(ii) Explain why the colour of the indicator in the sample of rainwater is pale orange whereas in pure water it is green.

(iii) A given crystalline solid is suspected to be either sodium chloride or ammonium tetraoxosulphate (VI). Describe how you would use the indicator to identify the solid.

(iv) State with reason whether or not phenolphthalein indicator can be used to distinguish between the samples of glucose solution and vinegar.

(v) What would be the colour of methyl orange indicator in the lime water sample? 

A is a solution containing 0.50 mole of barium chloride per dm\(^3\). Solution B contains 1.0 mole of tricxocarbonate (IV) salt per dm\(^3\)

(a) State what would be observed and give the confirmatory test for any gases evolved if the following tests were performed

(i) mixing 2cm\(^3\) each of solutions A and B in a test tube

(ii) adding excess dilute hydrochloric acid to the mixture from (a)(i) above

(b) 10cm\(^3\) of solution A were measured into each of seven boiling tubes of uniform bore and various quantities of solution B were added respectively to the boiling tubes, The tubes were immersed in hot water. After the reaction, the height of the product in each of the tubes was measured. The results were as tabulated below.

(i) Plot a graph of the height of the product against the volume of solution B added to each test tube. Explain the shape of the graph

(ii) Calculate the amount (in mole) of the trioxocarbonate (IV) salt contained in the volume of solution B added to tube lV

(iii) Calculate the amount (in mole) of barium chloride contained in 10cm\(^3\) of solution A. Hence, determine the mole ratio of barium chloride and the trioxocarbonate (IV) Salt in the reaction

C is a mixture of an organic and an inorganic salt. The test recorded in the table below were performed as indicated, 

(a)Copy and complete the table as appropriate. 

(b) From the information provided and your inference, identify the compounds of C 

(c) Describe the action of heat on a solid sample of the inorganic component  Write an equation for the reaction.

(d) State what would be observed if an aqueous suspension of the organic component were heated to boiling 

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.