1991
C is a mixture of an organic and an inorganic salt. The test recorded in the table below were performed as indicated, (a)Copy and complete the table as appropriate. Test ObservationInference(i) C + water mixed thoroughly…
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1991 WAEC SSCE Chemistry Past Questions
1991
A is a solution containing 0.50 mole of barium chloride per dm\(^3\). Solution B contains 1.0 mole of tricxocarbonate (IV) salt per dm\(^3\)(a) State what would be observed and give the confirmatory test for any gases ev…
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1991
(a) Name the apparatus used in the laboratory to (i) Convert vapour into liquid during distillation(ii) determine the volumetric composition of water(ii) produce an intermittent supply of any gas which can be evolved by…
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1991
(a) State two factors which can affect the rate of a chemical reaction.(b) 0.72g of magnesium was added to different volumes of 2 mol. per dm\(^3\) hydrochloric acid. The volume of liberated was as measured at room tempe…
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1991
(a) Give three differences between electrovalent compounds and covalent compounds (b) List two physical properties of metals which can be accounted for by their structure(c) Thorium (Th) metal undergoes a reaction repres…
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1991
(a) Name one gaseous hydrocarbon which is(i) used for welding.(ii) a major raw material for the plastic industry.(b) Write the structural formula of the hydrocarbon in (a)(i) above. Name the process by which it can be co…
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1991
(a)(i) Give two uses of chlorine.(ii) State the action of chlorine on moist blue litmus paper(b) Draw a labelled diagram for the laboratory preparation of a dry sample of chlorine(c) State the type of reaction involved b…
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1991
The set-up shown in the diagram below was used to separate a drop of universal indicator into the constituent dyes using ethyl ethanoate as the solvent.(a) What name is given to the separate strated in the diagram?(b) St…
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1991
Sketch a curve to show how the solubility of a gas varies with increasing temperature
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1991
Give one oxide in each case which;(a) can act as a reducing agent(b) can be used as a refrigerant(c) is the anhydride of a strong acid;(d) is yellow when hot and white then hot and white when cold;(f) is usad as a pigme…
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1991
(a) Name the industrial process by which ethene is obtained from petroleum fractions(b) Give the I. U. P.A.C name of the isomer whose structure is shown below.(c) Illustrate with an equation, one reaction in which benzen…
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1991
(a) Give two reasons why fused alumina is mixed with cryolite in the electrolytic extraction of aluminium.(b) Write an equation for the reaction of sodium hydroxide with bauxite.
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1991
(a) Give the products of electrolysis of dilute copper (II) tetraoxosulphate(VI) solution using the following materials as electrodes:(i) carbon rod;(ii) copper rods(b) For each of the process in (a) above;(i) write the…
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1991
Methane is obtained when a powdered mixture of anhydrous sodium ethanoate and soda-lime is heated in a hard glass test tube.(a) Write an equation for the reaction.b) Explain briefly why soda-lime is preferred to sodium…
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1991
A colourless and odourless gas X burns in oxygen with a pale blue flame.(a) Suggest two gases which X could be.(b) Give one chemical test that could be used to confirm which of the two gases X is.
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1991
(a)State three characteristics of a catalyst.(b) Mention one manufacturing process in which each of the following metals is used as a catalyst:(i) iron;(ii) nickel;(iii) platinum(c) Give one example of an organic catalys…
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1991
State the atoms represented as shown below:(a) State the relationship between the two atoms.(b) What is the difference between them?(c) Give two examples of elements which exhibit the phenomenon illustrated above.
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1991
The separation of a mixture of calcium trioxocarbonate (lV) and sodium trioxocarbonate (IV) is most easily carried out by using the differences in their
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1991
In which of the following is the oxidation number of nitrogen zero?
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1991
The metal extracted from cassiterite is
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