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.

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

50 questions
Question 1 of 20 50 total questions
Question 11
jamb 2004

The allotrope of carbon used in the decolourization of sugar is

AGraphite
BSoot
CCharcoal
DLampblack
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Question 12
jamb 2004

Which of the following shows little or no net reaction when the volume of the system is decreased?

AH2(g) + I2(g) ↔ 2HI(g)
B2NO2(g) ↔ N2O4(g)
CPCl5(g) ↔ PCl3(g) + Cl2(g)
D2O3(g) ↔ 3O2(g)
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Question 13
jamb 2004

N\(_2\)O\(_4\),(g) ↔ 2NO\(_2\)(g)
In the endothermic reaction above, more product formation will be favoured by

Aa constant volume
Ban increase in pressure
Ca decrease in pressure
Da decrease in volume
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Question 14
jamb 2004

Which of the following hydrogen halides has the highest entropy value?

AHF
BHCl
CHBr
DHI
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Question 15
jamb 2004

2CO(g) + O\(_2\)(g) → 2CO\(_2\)(g)
Given that ΔH[CO]is -110.4 kJmol-1 and ΔH[CO\(_2\)] is -393.0 kJmol-1, the energy change for the reaction above is

A-503.7 kJ
B-282.6 kJ
C+282.6 kJ
D+503.7 kJ
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Question 16
jamb 2004

The mass of silver deposited when a current of 10A is passed through a solution of silver salt for 4830s is
[Ag = 108, 1F = 96500 Cmol-1]

A108.0g
B54.0g
C27.0g
D13.5g
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Question 17
jamb 2004

In the electrolysis of brine, the anode is

Aplatinum
Bcopper
Czinc
Dcarbon
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Question 18
jamb 2004

Which of the following acts as both reducing and oxidizing agent?

AH2
BSO2
CH2S
DCO2
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Question 19
jamb 2004

ZnO(s) + CO(g) → Zn(s) + CO\(_2\)(g)
In the reaction above, Zinc has been

Adecomposed
Bdisplaced
Coxidized
Dreduced
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Question 20
jamb 2004

The oxidation state of chlorine in HClO\(_4\) is

A-5
B-1
C+1
D+7
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Question 21
jamb 2004

What volume of 0.5 mol dm\(^{-3}\) H\(_2\)SO\(_4\) will exactly neutralize 20cm\(^3\) of 0.1 mol dm\(^{-3}\) NaOH solution?

A2.0 cm3
B5.0 cm3
C6.8 cm3
D8.3 cm3
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Question 22
jamb 2004

Which of the following compound is a normal salt?

ANaHS
BNaHSO4
CNaHCO3
DNa2CO3
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Question 23
jamb 2004

Calcium tetraoxosulphate (VI) dissolves in water only sparingly to form a

Asolution
Bsuspension
Cprecipitate
Dcolloid
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Question 24
jamb 2004

The solubility in moldm\(^{-3}\) of 20g of CuSO\(_4\) dissolved in 100g of water at 180\(^o\)C is
[Cu = 64, S = 32, O =16]

A0.13
B0.25
C1.25
D2.00
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Question 25
jamb 2004

A carcinogenic substance is

Aasbestos dust
Bsawdust
Cnitrogen (II) oxide
Dcarbon (II) oxide
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Question 26
jamb 2004

Pollution of underground water by metal ions is very likely in the soil that has high

Aacidity
Balkalinity
Cchloride content
Dnitrate content
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Question 27
jamb 2004

Hardness of water is caused by the presence of ions of

Amagnesium and silver
Bcalcium and magnesium
Csodium and potassium
Dcalcium and sodium
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Question 28
jamb 2004

Which of the following mixture of gases is likely to burn in flame?

Aneon and hydrogen
Bnitrogen and helium
Chelium and neon
Dneon and nitrogen
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Question 29
jamb 2004

Chlorine consisting of two isotopes of mass number 35 and 37 in the ratio 3:1 has an atomic mass of 35.5. Calculate the relative abundance of the isotopes of mass number 37

A20
B25
C60
D75
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Question 30
jamb 2004

The property of chlorine which causes hydrogen chloride to be more ionic than the chlorine molecules is its

Aelectrovalency
Belectron affinity
Celectropositivity
Delectronegativity
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