(a) State how you would carry out the following procedures in the laboratory:

(i) Remove the sediment in sample of water;

(ii) Soften temporarily hard water without heating it,

(iii) Obtain pure water frdm muddy water;

(iv) Remove oxygen and moisture from a sample of air

(b)(i) What type of salts are alums?

(ii) State the function of alum in water treatment plants.

(iii) State and explain how rain water that hac passed through limestone deposits will react with soap solution.

(c)(i) Write an equation for the laboraton preparation of chlorine

(ii) List the products of the reaction of chorine with hot concentrated sodiuri hydroxide solution

(iii) What is observed when moist blue litmus paper comes in contact with chlorine?

(iv) Calculate the volume of chlorine at s.t.p. that would be required to react completely with 3.70g of dry slaked lime according to the following equation:

Ca(OH)\(_{2(s)}\) + Cl\(_{2(g)}\) --> CaOCl\(_{2}\). H\(_2\)O\(_{(s)}\)  [H = 1, O = 16, Ca = 40, 1 mole of gas occupies 22.4 dm\(^3\) at s.t.p.]

(d)(i) State what is observed on warming ammonium trioxonitrate (V) with sodium hydroxide solution

(ii) Explain why ammonium trioxocarbonate (IV) leaves no residue on being heated.

(a) Name one laboratory equipment used for

(i) keeping salts dry:

(ii) converting vapour to liquid during distillation

(ii) bubbling a gas into a liquid

(b) (i) What technique would you use to purity a sample of sodium chloride contaminated with ammonium chloride?

(i) Given sodium hydroxide solution, outline tne procedure you would use to determine whether or not all the ammonium chloride in (b)(i) above had been removed

(c) State what is observed on carrying out each of the following exercises.

(i) Adding few drops of methyl orange indicator to lime juice:

(ii) Adding few drops of concentrated HNO\(_3\) to acidified FeSO\(_4\) solution

(iii) Exposing a fresh precipitate of silver chloride to sunlight for 30 minutes

(iv) Adding zinc dust to dilute CuCl\(_2\) solution;

(v) Adding dilute H\(_2\)SO\(_4\), to Pb(NO\(_3\))\(_2\) solution

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.

C is a mixture of two simple salts. Carry out the following exercises on C. Record your observations and identify any gases evolved. Sate the conclusion you draw from the result of each test.

(a) Put all of C into a beaker of boiling tube and add about 10cm\(^3\) of distilled water. Stir well and filter. Keep the residue and keep the residue and the filtrate. Test the filtrate with litmus

(b) Add about 1 cm\(^3\) of dilute hydrochloric acid to the residue in a test tube  and warm gently Divide the reaction mixture into two portions

(c)(i) To the first portion from (b) add saturated sodiuim trioxocarbonate (V) solution in excess

(d) To bout 2cm\(^2\) of the filtrate from (a) add a few drops of barium chloride solution followed by excess dilute hydrochloric acid 

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.

A is solution of trioxonitrate (V) acid, B is a solution containing 6.90 g of potassium trioxocarbonate (IV) per dm\(^3\)

(a) Put A into the buret and titrate it against 20.0 cm\(^3\) or 25.0 cm\(^3\) portions of B using methy orange or screened methyl orange as indicater. Record the volume of your pipette. Tabulate your burette readings and calculate the average volume A used. The equation for the reaction is K\(_2\)CO\(_{3(aq)}\) +  2HNO\(_{3(aq)}\) \(\to\) 2KNO\(_{3(aq)}\) + CO\(_{2(g)}\) +  H\(_2\)O\(_{(l)}\)

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

(i) concenytration of solution B in mol dm\(^{-3}\)

(ii) number of potassium ions in 1.00 dm\(^3\) of B [C = 12.0, O = 16.0, K = 39.0, Avogadro constant = 6.02 x 10\(^{23}\) mol \(^{-1}\)]