Study and practice Chemistry past questions with answers and detailed explanations. Then test your knowledge using our interactive CBT practice platform and prepare confidently for your upcoming examinations.
Which of the following processes will pollute water?
AExposure of a body of water ultraviolet rays
BDischarge of industrial effluents effluents into water ways
CPassage of river water through a send bed
DAddition of a measured quantity of chlorine to water
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Question 2
waec2003
What are the two gases associated with the formation of acid rain?
ACO2 and HCI
BCO2 and N2
CCO2 and NO2
DHCI ans SO2
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Question 3
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When a sample of water was boiled, it lathered more readily with soap. it can be concluded that the sample most likely contained
Amagnesium tetraoxosulphate (VI)
Bsuspended solids
COrganic impurities
Dcalcium hydrogentrioxocarbonate (IV)
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Question 4
waec2003
What is the main impurity in haematite?
ACaSiO3
BCaCO3
CSiO3
DFe2O3
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Question 5
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Which of the following compound is used for removing impurities from bauxite?
ANaOH
BCaCO3
CNa3AIF6
DH2SO4
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Question 6
waec2003
What volume of 0.20 mol dm -3 NaOH solution would yield 5.0 g of NaOH on evaporation to dryness? [NaOH = 40g mol-1]
A400 cm3
B625 cm3
C1000 cm3
D1600 cm 3
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Question 7
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When excess ethene is shaken with acidified KMnO4 solution, the product obtained is
Aethane
Bethanal
Cethane - 1, 2 - diol
Dethanoic acid
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Question 8
waec2003
What process does the following equation represent ? n(C\(_{6}\)H\(_{10}\)O\(_{5}\)) + nH\(_{2}\)O → nC\(_{6}\)H\(_{12}\)O\(_{6}\) ?
APolymerization of glucose
BHydrolysis of starch
CFermentation of sugar
DDehydration of carbohydates
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Question 9
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The reaction of vegetable oil with a solution of wood ash is
Asaponification
Bneutralization
Chydrogenation
Desterification
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Question 10
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What is the organic product of the reaction of C2H 5OH with excess acidified K 2Cr 2O7(aq)?
ACH3COOH
BC2H5OC2H5
CHCOOCH 3
DC2H5CHO
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Question 11
waec2003
Which of the following substances could be responsible for the banana taste of a food flavour?
AMethylbenzene
BButanol
CEthanol
DPentylethanoate
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Question 12
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Wine containing 8% to 17% ethanol can be converted to gin containing about 40% ethanol by
Aevaporation
Bdistilation
Cfermentation
Doxidation
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Question 13
waec2003
A given fuel has an octane number of 100. This means that
Athe knocking tendency of the fuel is low
Bthe fuel is a mixture of several hydrocarbons
Ca large amount of alkanes is present in the fuel
Dthe fuel needs to be cracked before use
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Question 14
waec2003
Which of the following compounds has the same empirical formula as benzene?
AC2H2
BC2H4
CC4H6
DC6H12
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Question 15
waec2003
The equation for the reaction at the anode during the electrolysis of concentrated sodium chloride solution is
A2CI-(aq) → CI,sub>2(g) + 2e-
B40H-(aq) → 2H2O(I) + O2(g) + 4e -
CNa+(aq) + e- → Na(s)
D2H+(aq) + 2e- → H2(g)
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Question 16
waec2003
A given fuel has an octane number of 100. This means that
Athe knocking tendency of the fuel is low
Bthe fuel is a mixture of several hydrocarbons
Ca large amount of alkanes is present in the fuel
Dthe fuel needs to be cracked before use
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Question 17
waec2003
Determine the amount of electrons needed to deposit 6.4g of copper during the electrolysis of copper (ll) tetraoxosulphate (IV) solution [Cu = 64]
A0.10 mole
B0.20 mole
C1.0 mole
D2.0 mole
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Question 18
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Which of the following statements is/are correct about tin plating? l The electrolyte must be a soluble salt of tin ll. the objective to be plated is made the cathode lll. The anode is made of tin lV. The negative electrode dissolves
AL only
Bl and ll only
Cl,ll and lll only
Dl, ll and lV only
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Question 19
waec2003
Five metals represented by the letters V to Z are arranged in order of their reactivity as shown . V>W>X>Y>Z.
Which of the metals is most likely extracted by the electrolysis of its fused chloride?
AV
BW
CX
DZ
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Question 20
waec2003
Five metals represented by the letters V to Z are arranged in order of their reactivity as shown . V>W>X>Y>Z.
Which of the metals cannot displace Y from an aqueous solution of its salt?
