Chemistry Past Questions

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

159 questions
Question 1 of 20 159 total questions
Question 1
waec 2025

Empirical formula is the 

Asimplest formula of a compound
Bmolecular formula of a compound
Cchemical formula of a compound
Dstructural formula of a compound
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Question 2
waec 2025

When a hypothesis is proven within the limit of available evidence, it becomes a 

Ascope
Btheory
Cprinciple
Dlaw
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Question 3
waec 2025

When C\(_2\)H\(_4\) molecule is polymerized, the polymer formed is 

Apolyethene
Bpolyethane
Cpolypropene
Dpolybutene
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Question 4
waec 2025

A few drops of sodium hydroxide is added to an aqueous solution, a green precipitate is formed. The ion that may be present in the solution is 

ACu\(^{2+}\)
BFe\(^{2+}\)
CFe\(^{3+}\)
DNH\(_4\)\(^{+}\)
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Question 5
waec 2025

Nucleons are sub-atomic particles which consist of

Aprotons and neutrons
Bneutrons and electrons
Cprotons and electrons
Dneutrons, protons and electrons
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Question 6
waec 2025

In the periodic table, valence electrons are indicated by 

Agroup number
BShell number
Cperiod number
Datomic mass
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Question 7
waec 2025

The allotrope of carbon used in the decolourization of sugar is 

Acharcoal
Bgraphite
Clampblack
Dsoot
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Question 8
waec 2025

Which of the following oxides is amphoteric?

ACaO
BMgO
CBaO
DBeO
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Question 9
waec 2025

Five d-orbitals have the same energy level in an isolated transition metal are described as 

Adegenerate
Bnon-degenerate
Chigh level orbital
Dlow-level orbital
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Question 10
waec 2025

Which of the following metals would not release hydrogen when reacted with dilute HCl?

ACalcium
BSilver
CIron
DZinc
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Question 11
waec 2025

Exothermic reactions take place when energy given out in making bonds is 

Aless than energy in for breaking bonds
Bmore than energy taken in for breaking bonds
Cequal to the energy taken in for breaking bonds
Dremains the same as the energy taken in
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Question 12
waec 2025

The lustre of a metal is due to its

Ahigh density
Brefractive density
Cchemical inertness
Dfree electrons
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Question 13
waec 2025

Which of the following elements is commercially obtained by the electrolysis of its fused salt?

ASilver
BCopper
CHelium
DSodium
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Question 14
waec 2025

Which of the following alkanols is tertiary?

A2-methylpentan-2-ol
B2-methylpentan-1-ol
Cpentan-3-ol
Dpentan-2-ol
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Question 15
waec 2025

The electron configuration of element Y is 1S\(^2\)2S\(^2\)2P\(^6\)3S\(^2\)3P\(^4\). Y, therefore,

Ahas mass number of 16
Bhas three unpaired electron
Cbelongs to period 4
Dbelongs to group VI
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Question 16
waec 2025

Which of the following species is the most powerful reducing agent?

ABromine atom
BChlorine atom
CFluoride atom
DIodine atom
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Question 17
waec 2025

Neutral atom of Neon with atomic number 10 is isoelectronic with

AK\(^+\)
BMg\(^{2+}\)
CCa\(^{2+}\)
DLi\(^+\)
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Question 18
waec 2025

The IUPAC name of the compound CH\(_3\)CHClCH\(_2\)OH is

Achloropropanol
B1-chloropropan-1-ol
C2-chloropropan-3-ol
D2-chloropropan-1-ol
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Question 19
waec 2025

A salt that could be prepared by double decomposition is 

Asodium trioxocarbonate (IV)
Bbarium trioxonitrate (V)
Clead (II) trioxonitrate (V)
Dsilver chloride
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Question 20
waec 2025

All the following compounds are covalent except

ANO\(_2\)
BSO\(_3\)
CSO\(_2\)
DKNO\(_3\)
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