(a) (i) List two gaseous pollutants that can be generated by burning coal.
(ii) Explain briefly why coal burns more easily when it is broken into pieces than when it is in lumps.
(iii What gas is responsible for most of the explosions in coal mines?
(iv) Name the non-volatile residue left behind after the destructive distillation of coal.
(b) State one oxide in each case which:
(i) is used in bleaching;
(ii) oxidizes hot concentrated HCl to chlorine;
(iii) dissolves in water to give a solution with pH greater than 7;
(iv) reacts with NaOH and also with HCl;
(v) is a reddish-brown gas.
(c) (i) Write a balanced chemical equation for the reaction between chlorine gas and iron(II) chloride solution.
(ii) State the type of reaction in (c)(i).
(iii) Give a reason for your answer in (c)(ii).
(d) Consider the following set-up:
(i) Identify A and B.
(ii) Write a balanced chemical equation for the reaction.
(iii) Name the gas produced.
(iv) Why was the flask tilted downwards?
(v) What is the:
(I) function of B in the experiment;
(II) method of collection of the gas?
(e) Give one product obtained from refining petroleum that is solid.
All your burette readings (initials and final) as well as the size of your pipette must he recorded but no account of experimental procedure is required. All calculations must be done in your booklet.
A solution of potassium tetraoxomanganate( VII). B is a solution of iron(II)chloride containing 4.80g of the salt in 250 cm\(^{3}\) of solution.
(a) Put A into the burette. Pipette 20.0cm\(^3\) or 2.50.0 of B into a conical flask, add 20.0 cm\(^3\) of H\(_2\)SO4\(_{(aq)}\) and titrate with A. Repeat the titration to obtain concordant titre values. Tabulate your results and calculate the average volume of A used. The equation of the reaction is: MnO\(_{4(aq)}\) + 5Fe\(^{3+}_{ (aq)}\) + H\(_2\))
(b) From your results and the information provided, calculate the;
(i) concentration of B moldm\(^{-3}\):
(ii) concentration of A in moldm\(^{-3}\)
(iii) number of moles of Fe\(^{2+}\) in the volume of B pipetted. [FeCl\(_2\) = 127 gmol\(^{-1}\)] Credit will be given for strict adherence to the instruction, for observations precisely recorded and for accurate inferences. AlI tests, Observations and inferences must be clearly entered in the booklet in ink at the time they are made.
All your burette readings (initials 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 booklet.
C and D are inorganic salts. Carry out the following exercises on them. Record your observations and identify any gas(es) evolved. State the conclusions you draw from the result of each test.
(a) Put all of C in a test tube and add about 5 cm of distilled water. Shake thoroughly and test the resulting solution with Litmus paper. Divide the solution into three portions.
(i) To the first portion, add NaOH\(_{(aq)}\) in drops, then in excess.
(ii) To the second portion. add NH\(_{3(aq)}\) in drops. then in excess.
(iii) To the third portion. add AgNO\(_{3 (aq)}\) followed by HCl\(_{(aq)}\)
(b)(i) Put all of D in a test tube and add about 5 cm\(^3\) of distilled water. Shakę thoroughly and feel the test tube.
(ii) To about 2 cm\(^3\) of the solution, add HCl\(_{(aq)}\)
All your burette readings (initials and final) as well as the size of your pipette must he recorded but no account of experimental procedure is required. All calculations must be done in your booklet.
State the observation that would be made when each of the following reactions is carried out in the laboratory:
(a) Addition of 2 cm\(^3\) of bench H\(_2\)SO\(_{4(aq)}\) to 2 cm\(^{3}\) of barium chloride solution;
(b) Addition of 2 cm\(^3\) of dilute hydrochloric acid to 1g of powered iron(II) sulphide (FeS):
(C) Addition of 2 cm\(^3\) of dilute hydrochloric acid to 1g of iron filings and allowed to stand for sometime.
