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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.

2,505 questions JAMB 2505 WAEC 1623 NECO 168 CUSTOM 10
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Past Questions

2,505 questions
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Question 1 of 20 2,505 total questions
Question 411
jamb 2014
The major and most effective way of controlling pollution is to
Aimprove machinery so that the substances released from combustion are less harmful
Bpass strict laws against it by individuals and companies
Ceducate people on the causes and effects of pollution
Dconvert chemical wastes to harmless substances before releasing them into the environment
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Question 412
jamb 2014
The dispersion of a liquid in a liquid medium will give
Aan emulsion
Ba fog
Ca gel
Dan aerosol
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Question 413
jamb 2014

16.55g of lead (ll) trioxonitrate (V) was dissolved in 100g of distilled water at 20oC, calculate the solubility of the solute in moldm-3

[Pb = 207, N = 14, O = 16]

A0.05 g
B2.00 g
C1.00 g
D0.50g
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Question 414
jamb 2014

On exposure to the atmosphere, a hydrated salt loses its water of crystallization to become anhydrous. This phenomenon is referred to as

Aefflorescence
Bdeliquescence
Chygroscopy
Dhydrolysis
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Question 415
jamb 2014

Water is said to be temporarily hard when it contains

ACa (HCO3)2 and Mg (HCO3)2 salts
BCa (HCO3)2 and CaCO3 SALTS
CMg(HCO3)2 and CaSO4 salts
DCaSO4 and Ca(HCO3)2 salts
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Question 416
jamb 2014

A silicon -containing ore has 92% 28Si, 5% 29Si and 3% 30Si. Calculate the relative atomic mass of the silicon.

A14.00
B29.00
C28.11
D28.00
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Question 417
jamb 2014
The radio active radiation used in studying the arrangement of particles in giant organic molecules is
A\(\gamma\)- rays
B\(\alpha\)- particles
CX-rays
D\(\beta\) - particles
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Question 418
jamb 2014
How many protons, neutrons and electrons respectively are present in the element 60/27 Co?
A27, 33 and 33
B33, 27 and 27
C27, 33, and 27
D60, 33 and 60
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Question 419
jamb 2014
If the difference in electronegativity of elements P and Q is 3.0. The bond that will be formed between them is
Ametallic
Bcovalent
Cco-ordinate
Dionic
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Question 420
jamb 2014

Beryllium and aluminum have similar properties because they?

Aare both metals
Bbelong to the same group
Cbelong to the same period
Dare positioned diagonally to each other
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Question 421
jamb 2014
An element X has electron configuration 1s2 2s2 2p6 3s2 3p5. Which of the following statements is correct about the element?
Alt has a completely filled p-orbital
Blt has 5 electrons in its outermost shell.
Clt belongs to group ll on the periodic table
Dlt is a halogen
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Question 422
jamb 2014

200 cm3 of a gas at 25ºC exerts a pressure of 700 mmHg. Calculate its pressure if its volume increase 350 cm3 at 75ºC.

A342.53 mmHg
B1430.54 mmHg
C467.11 mmHg
D400.00 mmHg
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Question 423
jamb 2014
A gas X diffuses twice as fast as gas Y. if the relative molecular mass of X is 32, calculate the relative molecular mass of Y.
A128
B8
C16
D64
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Question 424
jamb 2014
What is the percentage of sulphur in sulphur (IV) oxide?
A66%
B25%
C40%
D50%
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Question 425
jamb 2014
A mixture is different from a compound because
Athe properties of a compound are those of its individual constituents while those of a mixture differ from its constituents
Ba mixture is always homogeneous while a compound is not
Cthe constituent of a compound are chemically bound together while those of a mixture are not
Da mixture can be represented by a chemical formula while a compound cannot
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Question 426
jamb 2013
2SO2(g) + O2(g) \( \iff \)2SO3(g)

\( \bigtriangleup H = -395.7kJmol^{-1} \)

In the reaction above, the concentration of 2SO3(g) can be in creased by
Adecreasing the pressure
Bdecreasing the temperature
Cthe addition of catalyst
Dincreasing the temperature
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Question 427
jamb 2013
Zn(s) + CuSO4(aq) \( \to \) ZnSO4(aq) + Cu(s)

In the reaction above, the oxidizing agent is
ACuSO4(aq)
BZnSO4(aq)
CCu(s)
DZn(s)
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Question 428
jamb 2013
The radioactive emission with the least ionization power is
A\( \alpha - particles \)
BX-rays
C\( \gamma -rays \)
D\( \beta - rays \)
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Question 429
jamb 2013
How many unpaired electron are in the p-orbitals of a fluorine atom?
A3
B\( 0 \)
C1
D2
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Question 430
jamb 2013
The compound above is an
Aalkanone
Balkanoate
Calkanal
Dakanol
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