(a) Methane reacts with chlorine under certain condition to produce tetrachloromethane.
(i) State the condition for the reaction
(ii) Name the type of reaction
(iii) Give two uses of methane
(iv) Name one major natural source of methane
(b)(i) Mention one similarity between the reaction of ethanol with sodium and that of sodium with water
(ii) Write the structure of two isomers of C\(_3\)H\(_8\)O
(iii) Differentiate between a fine chemical and a heavy chemical
(iv) Give one example of each in (b)(iii) above
(c) Two compounds X and Y have the same percentage composition by mass of 92.3% carbon and 7.7% hydrogen. Calculate the:
(i) empirical formula of X and Y;
(ii) molecular formula of each compound if molar mass of X is 26 g and Y is 78g.
(d) A protein is boiled for a long time with dilute HCI and a reaction occurred.
(i) State the type of reaction that occurred
(ii) Name the major product formed
(iii) Give the functional groups present in (d)(ii) above.
(a)(i) State one physical method and one chemical method in each case by which the following can be removed:
I. Permanent hardness in water
II. A suspension of CaCO\(_3\) in water.
(ii) Give one disadvantage of hard water.
(b) Explain the following observations: (i) Crystals of washing soda become powdery on exposure to air for a long time
(ii) The concentration of chloride ions in 0.02 mol dm\(^{-3}\) calcium chloride solution is not the same s in 0.02 mol dm\(^{-3}\) sodium chloride solution.
(iii) Iron filings corrode faster than iron nails of the same mass.
(c)(i) Classify each of the following oxides as acidic, basic, neutral or amphoteric. I. ZnO II. CO III. NO\(_2\)
(ii) Give the formula of the acid anhydride of each of the following: I. H\(_2\)CO\(_3\) II. H\(_2\)SO\(_4\)
(iii) Give the IUPAC name of the following salts: I. COCl\(_2\) II. Mg(NO\(_3\))\(_2\).
(d)(i) Mention one pollutant associated with depletion of ozone layer in the atmosphere
(ii) Calculate the volume occupied by 0.125 mole of oxygen at 27°C and a pressure of 2.02 x 105 Nm\(^{-2}\) [I mole of gas occupies 22.4 dm\(^3\) at s.t.p; standard pressure = 1.01 x 105 Nm\(^{-2}\)]
(iii) State one process used for the industrial preparation of oxygen.
(a)(i) Give the reason why copper turnings dissolve in AgNO\(_3\) solution but remain insoluble in Pb(NO\(_3\) )\(_2\) solution.
(ii) Copper turnings of mass 1.06g were placed in 250 cm\(^3\) of 0.20 mol dm\(^{-3}\) AgNO\(_3\). Calculate the amourt of silver ions present. [Cu = 63.5]
(iii) Determine whether all the copper in (a)(ii) above will discolvo in the solution. The equation for the reaction is CU\(_{(S)}\) + 2Ag\(^+_{(aq)}\) --> Ag\(_{(aq)}\) + Cu\(^{2+}_{(aq)}\)
(b)(i) List cheicil properties of acids
(ii) Give two large scale uses of HNO\(_3\)
(iii) Write an equation for the action of heat on each of the following compounds: I. Pb(NO\(_3\))\(_2\)
Il. AgNO\(_3\).
(c)(i) State what would be observed if a piece of damp blue litmus paper is dropped into a glass jar of chlorine.
(ii) Name the type of reaction which occurs in (c)(i) above.
(iii) Give the property of chlorine which is exhibited in the reaction in (c)(i) above.
(i) Name two products obtained directly from the destructive distillation of coal.
(ii) Give one use of each product named in (d)(i) above.
(a) Give the reason in each case why it is necessary to:
(i) moisten a piece of litmus paper used in testing for the acidity or alkalinity of a gas.
(i) acidify the test solution with dilute hydrochloric acid in the confirmatory test for SO\(_4^2\)
(b)(i) List two gases that must not be prepared in the open laboratory
(ii) Mention one precaution that should be taken in the laboratory to prevent excessive inhalation of these gases during their preparation.
(iii) State one use of each of the following pieces of apparatus in the laboratory. I. Wash bottle II. Tripod stand
(c) State what would be observed when:
(i) Pb(NO\(_3\))\(_2\) is needed
(ii) concentrated HCI is added to MnO\(_2\)
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 of HCI containing 5.0g dm\(^{-3}\). B is a solution of impure KOH containing 6.50g dm\(^{-3}\).
a) Put A into the burette and titrate it against 20.0 cm\(^3\) or 25.0 cm\(^3\) portions of B using methyl orange as indicator Tabulate your burette readings and calculate the average volume of A used. The equation for the reaction involved in the titration is: HCI\(_{(aq)}\) KOH\(_{(aq)}\) \(\to\) Cl\(_{(aq)}\) H\(_2\)O\(_{(l)}\)
(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) percentage purity of KOH in B [H= 1; CI = 35.5; KOH = 56.0g mol\(^{-1}\)]
