Chemistry Past Questions

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1,623 questions JAMB 2505 WAEC 1623 NECO 168 CUSTOM 10
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Past Questions

1,623 questions
Question 1 of 20 1,623 total questions
Question 71
waec 2023

Which of the following statements is correct?

AAddition reactions occur between alkanes and chlorine.
BButane has a lower boiling point than propane.
CPentane has five isomers.
DAn alkane with 49 carbon atoms contains 100 hydrogen atoms
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Question 72
waec 2023

Dilute trioxonitrate (V) acid does not produce hydrogen when it reacts with metals because

Ait reacts with the product.
Bit is highly corrosive.
Cthere is no visible reaction.
Dit is a strong oxidizing agent.
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Question 73
waec 2023

Which of the following properties does not give evidence of the kinetic theory of matter?

ADiffusion
BMelting
CPolymerization
DEvaporation
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Question 74
waec 2023

Which of the elements in the table below would react more readily with chlorine?
      

Element

Ionization energy (KJ \(mol^{-1} \times 10^{-3}\))

W 12.0
X 21.0
Y 106.0
Z 200.0

 

AY and Z only
BX and Z only
CW and X only
DW and Z only
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Question 75
waec 2023

The formation of a bond between hydrogen and a highly electronegative atom results in

Apolarity
Belectrovalent bond.
Cdipole
Dmetallic bond
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Question 76
waec 2023

Alkenes can be manufactured by

Athe combustion of alkanes.
Bthe cracking of hydrocarbons.
Cpolymerization reactions.
Daddition of hydrogen to unsaturated vegetable oils.
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Question 77
waec 2023

The following steps are scientific methods except

Aexperimentation
Bproblem identification
CAnalysis
DOpen-mindedness
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Question 78
waec 2023

Which of the following reactions represents the hydrolysis of an alkanoate?

A\(CH_3COOH + OH^- ⇌H^+⇌ CH_3COO^- + H_2O\)
B\(CH_3COOH + C_2H_5OH ⇌H^+⇌ CH_3COOC_2H_5 + H_2O\)
C\(CH_3COOC_2H_5 + H_2O ⇌H^+⇌ CH_3COO^- + CH_3CH_2OH\)
D\(CH_3COOCH_2CH_3 + H_2O ⇌H^+⇌ CH_3COOH + CH_3CH_2OH\)
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Question 79
waec 2023

The following statements are correct except

Aenergy is released when liquids change to solids.
Bcarbon atoms in gaseous methane are further apart than those in solid diamond.
Cthere is large decrease in the volume of a solid metal when pressure is applied to it.
Dparticles move faster in the gaseous state than in the liquid state.
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Question 80
waec 2023

The vapour density of an organic compound with the molecular formula \(C_2H_4O_2\), is
[H=1.0, C=12.0, O= 16.0]

A40
B120
C65
D30
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Question 81
waec 2022

Which of the following sketches is a graphical representation of Boyle's law?

AA
BB
CC
DD
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Question 82
waec 2022

Which of the following scientists formulated the law of conservation of mass?

AA. Lavoisier
BJ. Dalton
CR. Boyle
DJ. Proust
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Question 83
waec 2022

The first definition of an element was made by

AJ. Dalton.
BA. Lavoisier.
CR. Boyle.
DJ. J. Thompson.
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Question 84
waec 2022

Charcoal is used in the decolourization of sugar because of its

Aabsorption property.
Bamorphous property.
Coxidizing property.
Dadsorption property.
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Question 85
waec 2022

If the molar mass of X(HCO3)\(_{2}\) is 162 g mol\(^{-1}\), determine the relative atomic mass of X.
[H = 1.0, C = 12.0, 0 = 16.0]

A40
B48
C61
D101
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Question 86
waec 2022

Which of the following processes occur during fractional distillation of petroleum?

ACondensation and diffusion
BDiffusion and evaporation
CDiffusion and sublimation
DEvaporation and condensation
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Question 87
waec 2022

Which of the following oxides is amphoteric?

ACarbon(II) oxide
BNitrogen(IV) oxide
CLead(II) oxide
DCalcium oxide
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Question 88
waec 2022

Consider the following table

Substitute Meltig point / ºC Boiling  point / ºC
P - 78 -25
Q - 8 40
R  - 6 150
S 44 280


Which of the substances is a liquid at room temperature and rapidly evaporates on exposure to air?

AP
BQ
CR
DS
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Question 89
waec 2022

Electropositivity of elements across the periodic table normally

Aremains constant down the group
Bincreases across the period
Cdecreases across the period
Ddecreases down the group
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Question 90
waec 2022

The atom with the electron configuration
1s\(^{2}\)2s\(^{2}\)2p63s\(^{2}\)3p\(^{6}\)3d\(^{10}\)4s\(^{2}\)4p\(^{4}\) is in

Aperiod 4, p- block
Bperiod 3, p- block
Cperiod 4, d- block
Dperiod 3, d- block
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