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Chemistry Past Questions

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.

37 questions JAMB 2505 WAEC 1623 NECO 168 CUSTOM 10
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Past Questions

37 questions
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Question 1 of 17 37 total questions
Question 11
waec 1992
Consider the compounds represented by the following general formula: X2SO4 Y2(SO4)3, 24H2OX and Y could respectively be
AK and AI
BFe and K
CAI and Fe
DAI and K
ECr and K
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Question 12
waec 1992
When iron rusts, it undergoes
Adeliquescence
Bchemical decomposition
Chydrolysis
Dredox reaction
Ecombustion
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Question 13
waec 1992
What is the change in the oxidation number of phosphorus in the the reaction represented by the following equation? 4P (s) + 5O(2)(g) → 2P2O5(g)
A0 to + 2
B0 to 5
C+4 to + 2
D+4 to +5
E+4 to +7
View Explanation & Discuss
Question 14
waec 1992
What is the following compounds will not decompose when heated strongly ?
ANaHCO3
BK2CO3
CMgCO3
DCa(HCO3)2
EZnCO3
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Question 15
waec 1992
''The rate a reaction is proportional to the number of effective collisions occurring per second between the reactants''. This statement is associated with the
AKinetic theory
Brate law
Catomic theory
Dcollision theory
Egas laws
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Question 16
waec 1992

What is the quantity of electricity produced when a current of 0.5A is passed for 5 hours 45 mins? (1F = 96500C)

A0. 11F
B0.12F
C0.22F
D1.1F
E2.2F
View Explanation & Discuss
Question 17
waec 1992
The scum formed when soap is mixed with hard water could be
Acalcium trioxocarbonate (IV)
Bpropane- 1, 2, 3 - triol
Ccalcium hydrogentrioxocarbonate (IV)
Dmagnesium tetraoxosulphate (IV)
Ecalcium stearate
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Question 18
waec 1992
The halide used widely in photography is
Aammonium chloride
Bcalcum chloride
Csilver bromide
Dsodium brmide
Ealuminium fluroide
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Question 19
waec 1992
When air is passed through potash and then pyrogallol, the components are noble gases,
Aoxygen and carbon (IV) oxide
Boxygen and nitrogen
Cnitrogen and water vapour
Dwater vapour and carbon (IV) oxide
Eoxygen and water vapour
View Explanation & Discuss
Question 20
waec 1992
The reactions ethyne are mainly
Asubstitution reactions
Baddition reactions
Caddition polymerization
Dcatalytic hydrogenation
Ecatalytic halogenation
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Question 21
waec 1992
The following acids are monobasic except
Amethanoic acid
Bdioxonitrate lll acid
Cethanedioic acid
Doxochlorate (l) acid
Ehydrobromic acid
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Question 22
waec 1992

If the volume of a given mass of gas at 298 K and pressure of 205.2 x 10\(^3\) Nm\(^{-2}\) is 2.12dm\(^3\), what is volume of the gas at s.t.p? (Standard pressure = 101.3 x 10\(^3\) Nm\(^{-2}\), Standard temperature = 273K)

A39.3dm 3
B22.4dm3
C4.93dm3
D3.93dm3
E0.393dm3
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Question 23
waec 1992
Which of the following processes is a physical reaction?
AElectrolysis
BHydrolysis
CAllotropic change
DNeutralization
ECorrosion
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Question 24
waec 1992

Study carefully the reaction represented by the equation below. 2H2O 2(l) → O 2(g) + 2H2O(l). Which of the following will not reaction increase the reaction rate?

AHeating the hydrogen peroxide
BAdding a pinch of MnO2 to the reactant
Cincreasing the concentration of the H2O2
DAdding water to the reactant
EExposing the reactant to sunlight
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Question 25
waec 1992
Methanol is obtained from wood by
Aesterification
Bbacterial decomposition
Ccombustion
Dfractional distillation
Edestructive distillation
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Question 26
waec 1992
The maximum number of electrons that can accommodated in the shell having the principal quantum number 3 is
A3
B9
C10
D18
E32
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Question 27
waec 1992

When steam is passed over white-hot coke, the products are

Acarbon (IV) oxide and nitrogen
Bcarbon (II) oxide and hydrogen
Ccarbon (ll) oxide and nitrogen
Dcarbon (lV) oxide and steam
View Explanation & Discuss
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