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

A is a solution containing 6.3g dm\(^{-3}\) of impure ethanoic acid. B is 0.10mol. dm\(^{-3}\) sodium hydroxide sodium hydroxide solution.

(a) Put A into the burette and titrate with 20.0cm\(^3\) or 25.0cm\(^3\) portions of B using phenolphthalein as indicator. Record the volume of your pipette Record the volume of your pipette. Tabulate your burette readings and calculate the volume of A used.

(b) From your result and the information provided, calculate the

(i) concentration of solution A in mol.dm\(^{-3}\) 

(ii) Concentration of solution A in dm\(^{-3}\) and hence the percentage purity of the ethanoic acid,

(iii) Volume of solution A that would neutralize a solution containing 0.005 mole of sodium hydroxide. The equation for the reaction is;

H\(_2\)C\(_2\)O\(_{4(aq)}\) + 2NaOH\(_{(aq)}\) \(\to\) Na\(_2\)C\(_2\)O\(_{(aq)}\) + 2H\(_2\)O\(_{(l)}\) [H = 1; C = 12. O = 16]

(c)(i) What would be the colour of methylorange indicator in solution B?

(ii) Give the reason why methylorange is not a suitable indicator for titration. 

(a) Draw a labelled sketch of the laboratory set-up for dissolving hydrogen chloride acid.

(ii) Give one chemical test to distinguish between hydrochloric acid and ethanoic acid

(b) Outline a suitable laboratory procedure for obtaining a fairly pure sample of sodium chloride crystals from a solution of it that is contaminated with some methyl orange:

(c) Name one substance used in the laboratory for:

(i) drying ammonia gas,

(ii) testing for the presence of water;

(iii) converting copper (I) oxide to copper.

C and D are samples of two different simple salts. Carry out the following exercises on them. Record your observations and identify any gases evolved. State the conclusion you draw from the result of each test.

a) Heat about one-half of C in a dry test tube until no further change is observed. Allow to cool.

(b)(i) To the cooled residue from (a) above, add about 5cm\(^3\) of dilute hydrochloric acid and warm.

(ii) To about 2cm\(^3\) of the clear solution from (b)(i) above add aqueous ammonia in drops until it is in excess.

(c)  Put all of D in a boiling tube and add about 10cm\(^3\) of distilled water. Shake thoroughly and divide into two portions.

(d)(i) To the first portion from (c) above, add about 2cm\(^3\) of barium chloride solution, followed by dilute hydrochloric acid in excess. Warm the mixture.

(ii) To the second portion from (c) above, add 2 or 3 of acidified potassium tetraoxomanganate (VII) solution and shake.

A is a solution containing 0.050 mol. dm of tetraoxosulphate (VI) acid. B is a solution of anhydrous trioxocarbonate (IV).

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

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

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

(ii) mass of sodium tetraoxosulphate (VI) that would be formed in solution of 1dm\(^3\) of solution B were neutralized by solution A

(iii) volume of carbon (IV) oxide at s.t.p. that would be liberated in (b)(ii) above. The equation for the reaction is: N\(_2\)CO\(_{3(aq)}\) + H\(_2\)SO\(_{4(aq)}\) \(\to\)  Na\(_2\)SO\(_{4(aq)}\) + H\(_2\)O\(_{(l)}\) + CO\(_{2(g)}\) [O = 16; Na = 23, S = 32; molar volume of gases of s.t.p. = 22.4dm\(^3\) 

(a) State;

(i) One advantage:

(ii) One disadvantage of evaporation of salt solutions to dryness over crystallization.

(b)(i) List two normal salts which when dissolved in pure water are acidic to litmus

(ii) Mention the phenomenon that accounts for the behaviour of the salts in (b)(i) above.

(c)(i) Outline a suitable laboratory method for separating a mixture of glucose and starch.

(i) Give two chemical tests that would enable you to identify three solids suspected to be glucose, sucrose and starch.