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.

4,306 questions JAMB 2505 WAEC 1623 NECO 168 CUSTOM 10
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Past Questions

4,306 questions
Question 1 of 20 4,306 total questions
Question 541
waec 2017

The purity of a solid sample can best be determined by its

Aboiling point
Bmelting point
Cconductivity
Dsolubility
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Question 542
waec 2017

The seperation of Nitrogen from oxygen using fractional distillation of air is possible because

Anitrogen is less dense than oxygen
Boxygen is more reactive than nitrogen
Cof the difference in their boiling points
Dthey belong to the same period
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Question 543
waec 2017

The species with no electron in the 3d-orbital is

A\(Zn^{2+}\)
B\(Sc^{3+}\)
CCu
D\(Mn\)
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Question 544
waec 2017

Pauli exclusion principle is related to

Aquantity of electrons in the valence shell
Bfilling the orbitals with lower energy first
Cthe filling of degenerated orbitals
Dquantum numbers of electrons
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Question 545
waec 2017

The following glasswares are used to measure the volume of liquids EXCEPT

Agraduated beaker
Bpipette
Ctest tube
Dburette
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Question 546
waec 2017

Which of the following species determines the chemical properties of an atom?

AElectron
BNeutron
CNucleus
DProton
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Question 547
jamb 2017

X(g) + 3Y(g) ---- 2z(g) H = +ve. if the reaction above takes place at room temperature, the G will be

Anegative
Bzero
Cpositive
Dindeterminate
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Question 548
jamb 2017

Ca(OH)2(s) + 2NH4Cl(s) → CaCl2(s) + 2H2O(l) + X. In the reaction above X is

ANO2
BNH3
CN2O
DNO2
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Question 549
jamb 2017
Water for town supply is chlorinate to make it free from
Abad colour
Bbacteria
Ctemporary hardness
Dpermanent hardness
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Question 550
jamb 2017
The furring of kettles is caused by the presence in water of
Acalcium hydrogentrioxocarbonate (IV)
Bcalcium trioxocarbonate (IV)
Ccalcium tetraoxosulphate (VI)
Dcalcium hydroxide
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Question 551
jamb 2017
Due to the high reactivity of sodium, it is usually stored under
Awater
Bmercury
Cparaffin
Dphenol
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Question 552
jamb 2017
If 100cm3 of oxygen pass through a porous plug is 50 seconds, the time taken for the same volume of hydrogen to pass through the same porous plug is? [O = 16, H = 1]
A10.0s
B12.5s
C17.7s
D32.0s
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Question 553
jamb 2017

Calculate the amount in moles of a gas which occupies 10.5 dm3 at 6 atm and 30oC [R = 0.082 atm dm3 K-1 mol-1]

A2.536
B1.623
C4.736
D0.394
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Question 554
jamb 2017
Ethene is prepared industrially by
AReforming
BPolymerization
CDistillation
DCracking
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Question 555
jamb 2017

A particle that contains 9 protons, 10 neutrons and 10 electrons is

Apositive ion
Bneutral atom of a metal
Cneutral atom of a non-metal
Dnegative ion
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Question 556
jamb 2017
In the laboratory preparation of trioxonitrate (V) acid the nitrogen(iv) oxide formed as a by-product is removed by
Afurther heating
Badding concentrated H2SO4
Ccooling the acid solution with cold water
Dbubbling air through the acid solution
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Question 557
jamb 2017
The gas that can be collected by downward displacement of air is
Achlorine
Bsulphur (IV) oxide
Ccarbon (IV) oxide
Dammonia
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Question 558
jamb 2017
An oxide XO2 has a vapour density of 32. What is the atomic mass of X?
A20
B32
C14
D12
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Question 559
jamb 2017
According to Charle's law, the volume of a gas becomes zero at
A−100°c
B−273°c
C−373°c
D0°c
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Question 560
jamb 2017
The carbon atoms on ethane are
Asp2 hybridized
Bsp3 hybridized
Csp4 hybridized
Dsp hybridized
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