Chemistry Past Questions

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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 1
waec 2022

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

AA
BB
CC
DD
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Question 2
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 3
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 4
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 5
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 6
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 7
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 8
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 9
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 10
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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Question 11
waec 2022

Which of the following statements about atoms of a metal is correct? They

Areadily accept electrons
Bare soft
Care held together by covalent bond
Dare held together by a sea of electron cloud
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Question 12
waec 2022

An oxide has the following properties. It


I. is a white powder
II. reacts with HCI.
III. reacts with NaOH
IV. is insoluble in water
The oxide is

Aalkaline
Bamphoteric
Cacidic
Dneutral
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Question 13
waec 2022

The electron configuration of carbon atom in its excited state is

A1s\(^{2}\)2s\(^{2}\)2px\(^{1}\)2py\(^{1}\)
B
C1s\(^{2}\)2s\(^{1}\)2px\(^{1}\)2py\(^{1}\)2pz\(^{1}\)
D1s\(^{1}\)2s\(^{2}\)2px\(^{1}\)2py\(^{1}\)
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Question 14
waec 2022

Which of the following properties indicate that an element is a metal. It


I. reacts with oxygen to form an acidic oxide
II. forms ionic chlorides
III. has variable oxidation states
IV. displaces hydrogen from dilute HCl

AI and III only
BI and II only
CII and IV only
DI, II, III and IV
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Question 15
waec 2022

Ionization energy increases across the period in the periodic table because

Aatomic number increases
Beffective nuclear charge increases
Cmass number decreases
Dscreening effect decreases
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Question 16
waec 2022

The IUPAC name of the compound CH3CH(CH3)CHCH2 is

A2 - methyl but - 1 - ene
B2 - methyl but - 2 - ene
C3 - methyl but - 1 - ene
D3 - methyl but - 2 - ene
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Question 17
waec 2022

The maximum number of covalent bonds formed by nitrogen is

A1
B2
C3
D4
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Question 18
waec 2022

Which of the following bond types is intermolecular?

ACovalent bond
BHydrogen bond
CIonic bond
DMetallic bond
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Question 19
waec 2022

What is the percentage composition of carbon
in Ca(HCO3)\(_{2}\) ?
[ Ca = 40.0, 0= 16.0, C = 12.0, H= 1.0]

A22.2%
B14.8%
C7.4%
D3.7%
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Question 20
waec 2022

Which of the following elements would displace copper from a solution of copper ions?

Asilver
Bgold
Clead
Dmercury
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