Burette readings (initial and final) must be given to two decimal places. Volume or pipete used must also be recorded but no account of experimental procedure is required. All calculations must be done in your answer book.

A is a solution containing 12.0g dm\(^{-3}\) NaHSO\(_4\) NaHSO\(_4\) P is a solution containing NaOH

(a) Put A into the burette and titrate it against 20.0cm\(^3\) or 25.0m\(^3\) portions of B using methyl orange as an indicator. Repeat the titration to obtain consistent titres. Tabulate your readings and calculate the average volume A used. The equation for the reaction involved in the titration is ;

NaHSO\(_{4(aq)}\) + NaOH\(_{(aq)}\) \(\to\)  Na\(_2\)SO\(_{4(aq)}\) + H\(_2\)O\(_{(l)}\)

[H 1.00, O = 16.0; Na = 23.0, S = 32.0]

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

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

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

(iii) mass of Na\(^+\) formed in solution during the titration.

(a) List three pieces of apparatus required for the evaporation of sodium chloride solution to dryness.

(b)(i) List two normal salts which when dissolved in water turn red litmus blue.

(ii) State the phenomenon that is responsible for the action on the litmus in (b)(i).

(c) State what would be observed on adding BaCl\(_2\) solution to a portion of a saturated Na\(_2\)CO\(_3\), followed by dilute HCI in excess.

(i) A gas Q decolourized acidified KMnO\(_4\) solution. Suggest what Q could be.

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.

C is a mixture of two salts. Carry out the following exercises on C. Record your observations and identify any gas(es) evolved. State the conclusion you draw from the result of each test.

(a) Put all of C in a test tube and add about 10 cm\(^3\) of distilled water. Shake thoroughly and filter. Keep both the filtrate and the residue. Divide the filtrate into three portions.

(i) To the first portion, add NaOH\(_{(ag)}\) in drops and then in excess.

(ii) To the second portion, add NH\(_3\), solution in drops and then in excess.

(iii) To the third portion, add BaCl\(_{2(aq)}\) followed by dilute HCI.

(b) Divide the residue into two portions.

(i) Heat the first portion strongly in a test tube.

(ii) Add dilute HCI  to the second portion. 

Burette readings (initial and final reading) must be given to two decimal places. Volume of pipette used must also be recorded but no account of experimental procedure is required. All calculations must be done in your answer book.

A is 0.0950 mol dm\(^{-3}\) HCI. B is a solution 13.50g dm\(^{-3}\) of X\(_2\)CO\(_3\).10H\(_2\)O.

(a) Put A into the burette and titrate it against 20.0 cm\(^3\) or 25.0 cm\(^3\) portions öf B using methyl orange as an indicator. Tabulate your readings and calculate the average volume of A used.

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

(i) concentration of B in mol dm\(^{-3}\);

(ii) molar mass of X\(_2\)CO\(_3\).10H\(_2\)O in g mol\(^{-1}\);

(iii) percentage by mass X in X\(_2\)C)\(_3\).10H\(_2\)O. [H = 1, C = 12, O = 16]. The equation for the reaction involved in the titration is 2HCl\(_{(aq)}\) + X\(_2\)CO\(_3\).10H\(_2\)O\(_{(aq)}\) \(\to\) 2XCl\(_{(aq)}\) + 11H\(_2\)O\(_{(l)}\) + CO\(_{2(g)}\)  

(a) In the laboratory preparation of crystals of CuSO\(_4\), a green powder Q was added to dilute H\(_2\)SO\(_4\), and stirred. Effervescence occurred and a gas R was given off which turned lime water milky. Excess Q was removed from the mixture. The solution of Cu\(_2\)SO\(_4\) was concentrated to half its original volume and allowed to stand.

(i) What is substance Q?

(ii) Name gas R

(ii) Why was excess Q used?

(iv) How would you know that the reaction is complete?

(v) What method was used to remove excess Q? (vi) Why was the solution of CusO\(_4\) not heated to dryness?

(b) Name the reagent(s) used for testing each of the following substances in the laboratory: (i) Water; (i) Primary alkanol.