See WAEC GCE Chemistry 2017 Answers for Obj & Theory Questions Here.
Following the commencement of the West African Examination Council, WAEC, General Certificate Examination, GCE, the Chemistry exam paper will be written on Tuesday, 19th September, 2017.
The Gce Chemistry 2 (Essay) paper will start by 9:30am and will last for 2hrs while the chemistry 1 (Objective) exam will commence 11:30am and will last for 1hr.
In this post, we will be posting out samples of the waec gce commerce questions for candidates that will participate in the examination for practice purposes.
Related: WAEC GCE Commerce Answers 2017
WAEC GCE Chemistry Answers 2017:
1. Choose from the following compounds to answer the questions below.
Each compound can be used once, more than once or not at all.
Which compound is
(a) a solid, which when dissolved in water, gives a green precipitate with aqueous ammonia
(b) a colourless gas which is formed when limestone is heated strongly
(c) a gas which is formed in the atmosphere by lightning activity
(d) a basic oxide
(e) formed when ethane undergoes complete combustion
(f) a white salt which is insoluble in water?
2. Zinc sulfide is a compound that can be made by heating zinc powder with sulfur powder.
(a) Describe two differences between a mixture of zinc and sulfur and a compound of zinc
(b) The reaction between zinc and sulfur is exothermic. Complete the energy profile diagram for this reaction. On your diagram label the product, the enthalpy change for the reaction, ΔH.
(c) Part of the structure of zinc sulfide is shown below.
Deduce the empirical formula of zinc sulfide from this structure.
(d) Zinc sulfide reacts with hydrochloric acid to form hydrogen sulfide. An aqueous solution of hydrogen sulfide behaves as a weak acid.
Describe what is meant by the term weak acid.
(e) Zinc sulfate can be made by reacting zinc with dilute sulfuric acid.
Zn(s) + H2SO4(aq) ZnSO4(aq) + H2(g)
(i) Write an ionic equation for this reaction.
(ii) Describe how you would prepare crystals of pure, dry zinc sulfate using this reaction.
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3. Ethanoic acid reacts with sodium hydroxide to form water and a salt.
(a) Give the formula of the salt.
(b) The reaction between ethanoic acid and sodium hydroxide is described as a neutralisation reaction.
Write the simplest ionic equation for this reaction.
(c) Ethanoic acid reacts with methanol to form an ester and water.
CH3CO2H + CH3OH CH3CO2CH3 + H2O
The reaction is endothermic.
(i) Describe what happens to the position of this equilibrium when the concentration of methanol is increased. Explain your answer.
(ii) Describe what happens to the position of this equilibrium when the temperature of the reaction mixture is decreased. Explain your answer.
(d) The structure of the ester methyl benzoate is shown below.
Deduce the molecular formula for methyl benzoate.
(e) Sodium hydroxide is an alkali.
Give the formula of the ion present in sodium hydroxide which causes it to be alkaline.
(f) A student titrated a metal hydroxide with 0.200 mol/dm3 hydrochloric acid.
It required 12.5 cm3 of hydrochloric acid to neutralise 25.0 cm3 of 0.0500 mol / dm3 metal
(i) Calculate the amount, in moles, of hydrochloric acid used.
(ii) Calculate the amount, in moles, of metal hydroxide present.
(iii) Construct an equation for this reaction.
Use the letter M to represent the metal in the metal hydroxide solution.
(g) Name a metal hydroxide which can be used to treat excess acidity in soils.
Keep following, more questions and answers will be added soon.