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.

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

45 questions
Question 1 of 20 45 total questions
Question 11
jamb 2012

A metal M displaces zinc from ZnCl solution
This shows that

Aelectrons flow from zinc to M
BM is more electropositive than zinc
CM is more electonegative than zinc
Dzinc is more electropositive than M
View Explanation & Discuss
Question 12
jamb 2012

What number of moles of Cu 2+ will be deposited by 360 coulombs of electricity?
[f = 96500 C mol -1]

A5.36 x 10 -4 mole
B1. 87 x 10 10 -3 mole
C9. 35 x 10 -4 mole
D3. 73 x 10 -3
View Explanation & Discuss
Question 13
jamb 2012

2\(Na_2O_{2(s)} + 2H_2O_{(1)}\)→ 4\(NaOH_{(s)} +O_{2(g)}\)
The substance that is oxidized in the reaction above is

A\(Na_2O_{2(s)}\)
BNaOH(aq)
CH2O(1)
DO2(g)
View Explanation & Discuss
Question 14
jamb 2012
The oxidation number of boron in NaBH 4 is
A-3
B-1
C+1
D+3
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Question 15
jamb 2012
A major factor considered in selecting a suitable method for preparing a simple salt is its
ACrystalline from
Bmelting point
Creactivity with dilute acids
Dsolubility in water
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Question 16
jamb 2012
During a titration experiment, 0.05 moles of carbon (lV) oxide is liberated. What is the volume of gas liberated?
A22.40 dm 3
B11.20 dm 3
C2.24 dm 3
D1.12 dm 3
View Explanation & Discuss
Question 17
jamb 2012

The number of hydroxonium ions produced by one molecule of an acid in aqueous solution is its

Abasicity
Bacid strength
CpH
Dconcentration
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Question 18
jamb 2012

Which of the following will produce a solution with pH less than 7 at equivalent point?

AHNO 3 +NaOH
BH 2SO 4 + KOH
CHCL +Mg (OH) 2
DHNO 3 + KOH
View Explanation & Discuss
Question 19
jamb 2012

Which of the following pollutants is associated with brain damage?

ACarbon (ll) oxide
BRadioactive fallout
CBiodegradable waste
DSulphus (lV) oxide
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Question 20
jamb 2012

Potassium trioxochlorate (V)has a solubility of 1.5 mol dm -3 at 45 oC.On cooling this solution to a temperature of 20 oC, the solubility was found to be 0.5 mol dm -3. What mass of KCIO 3 was crystalized out?
[K = 39, Cl = 35.5 O =16]

A1.00g
B10.00g
C12.25g
D122.50g
View Explanation & Discuss
Question 21
jamb 2012
The solubilites of different solutes in a given solvent can be compared by
Aplotting their solubility curves on separete axes
Bplotting their solubility curves on the same axes
Cplotting some of the solubility curves on the x-axis and others on the y-axis
Dplotting their solubility curves on the x-axis only
View Explanation & Discuss
Question 22
jamb 2012
Chlorination of water for town supply is carried out to
Amake the water colourless
Bremove germs from the water
Cmake the water tastedful
Dremove odour from the water
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Question 23
jamb 2012
The chemicals used to soften hard water involves the addition of
Ainsoluble sodium compounds which from soluble solutions of calcium and magesium
Bsolube soudium compounds which from soluble solutions of calcium and magnesium ions
Csolube sodium compounds which from insoluble precipitates of calcium and magnesium ions
Dinsoluble precipitates of calcium and magnesium ions
View Explanation & Discuss
Question 24
jamb 2012

I. It has a varied composition from one place to another. ll. it constituents can be separated by physical means
lll. It contains unreactive noble gases
which of the above shows that air is a mixture?

AI and ll only
Bll and lll only
Cl and lll only
Dl,ll and lll
View Explanation & Discuss
Question 25
jamb 2012
Which of the following is used to study the arrangement of particles in crystal lattices?
AAlpha-particles
BBeta-particles
CGamma-rays
DX-rays
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Question 26
jamb 2012
Group VII elements are
Amonoatmic
Bgood oxidizing agents
Chighly electropositive
Delectron donors
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Question 27
jamb 2012
The electronic configuration of Mg 2+ is
Als 22s 22P 63s23P2
BIs22s22P6
Cls22s22p63s2
Dls22s22P4
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Question 28
jamb 2012

A hydrogen atom which has lost an electron contains

Aone proton only
Bone neutron only
Cone proton and one neutron
Done proton, one electron and one neutron
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Question 29
jamb 2012

If the elements X and Y have atomic numbers 11 and 17 respectively, what type of bond can they form?

ADative
BCovalent
CIonic
DMetallic
View Explanation & Discuss
Question 30
jamb 2012
l . Evaporation. ll. Sublimation. lll. Diffusion. IV. Brownian motion.
Which of the above can correctly be listed as evidences for the particulate nature of matter?
AI and lll only
Bll and lV only
Cl, ll and lll only
Dl, ll, lll and lV
View Explanation & Discuss
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