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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.

88 questions JAMB 2505 WAEC 1623 NECO 168 CUSTOM 10

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88 questions

Question 1 of 20 88 total questions

Question 31

jamb 2023

Which type of chemical combination involves the transfer of electrons from one atom to another, resulting in the formation of oppositely charged ions?

AIonic bonding

BHydrogen bonding

CCovalent bonding

DMetallic bonding

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Question 32

jamb 2023

What is the trend for ionization energy across a period in the periodic table?

AIncreases from left to right.

BRemains constant

CVaries randomly

DDecreases from left to right

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Question 33

jamb 2023

Balance the following redox reaction:
Fe\(_2\)O\(_3\) + CO → Fe + CO\(_2\)

AFe\(_2\)O\(_3\) + CO → 2Fe + 2CO\(_2\)

B2Fe\(_2\)O\(_3\) + 3CO → 4Fe + 3CO\(_2\)

CFe\(_2\)O\(_3\) + 2CO → 2Fe + 2CO\(_2\)

DFe\(_2\)O\(_3\) + 3CO → 2Fe + 3CO\(_2\)

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Question 34

jamb 2023

Identify the reducing agent in the following reaction:
Zn + CuSO\(_4\) → ZnSO\(_4\) + Cu

ACu

BZn

CZnSO\(_4\)

DCuSO\(_4\)

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Question 35

jamb 2023

What is the state of matter in which particles are widely spaced and move freely with high kinetic energy?

ALiquid

BSolid

CPlasma

DGas

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Question 36

jamb 2023

Stainless steel is an alloy made up of

AIron and zinc

BCopper and tin

CIron and chromium

DIron and carbon

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Question 37

jamb 2023

A gas occupies a volume of 1.5 liters at a pressure of 2 atmospheres. If the pressure is increased to 4 atmospheres while the temperature remains constant, what will be the new volume of the gas?

A6 liters

B1.5 liters

C0.75 liters

D3 liters

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Question 38

jamb 2023

What is Faraday's constant?

A6.022 x 10\(^{23}\) mol\(^{-1}\)

B3.00 x 10\(^8\) m/s

C9.81 m/s\(^2\)

D96,485 C/mol

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Question 39

jamb 2023

Which of the following methods can be used to remove temporary hardness from water?

ABoiling

BFiltration

Csedimentation

DChlorination

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Question 40

jamb 2023

Which trace gas in the atmosphere plays a significant role in the greenhouse effect?

AOxygen

BArgon

CCarbon dioxide

DNitrogen

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Question 41

jamb 2023

What is the solubility product constant (Ksp) used for?

ATo measure the total mass of a solute that can dissolve in a solvent

BTo determine the concentration of a solute in a saturated solution

CTo calculate the solubility of a solute in a given solvent

DTo compare the solubilities of different solutes in the same solvent

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Question 42

jamb 2023

What is the chemical structure of soap and detergent molecules?

AHydrophilic head and hydrophobic tail

BHydrophilic head and hydrophilic tail

CHydrophobic head and hydrophobic tail

DHydrophilic tail and hydrophobic head

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Question 43

jamb 2023

What happens to the value of the equilibrium constant (Kc) for a reaction if the reaction is reversed?

AIt becomes zero

BIt becomes negative

CIt remains the same

DIt becomes the reciprocal of the original value

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Question 44

jamb 2023

Which of the following is an example of an endothermic reaction?

ACombustion of propane (C\(_3\)H\(_8\)) to produce carbon dioxide (CO\(_2\)) and water (H\(_2\)O).

BBurning of methane (CH\(_4\)) in the presence of oxygen

CFormation of table salt (NaCl) from sodium (Na) and chlorine (Cl\(_2\)).

DDecomposition of hydrogen peroxide (H\(_2\)O\(_2\)) into water (H\(_2\)O) and oxygen (O\(_2\)).

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Question 45

jamb 2023

Who proposed the planetary model of the atom with electrons orbiting the nucleus?

AErwin Schrödinger

BErnest Rutherford

CNiels Bohr

DJ.J. Thomson

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Question 46

jamb 2023

What is the name of the process by which ammonia is produced on an industrial scale?

ANitrogenation

BAmmoniation

CNitrification

DHaber process

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Question 47

jamb 2023

What is eutrophication?

AThe release of harmful chemicals into water bodies

BThe excessive growth of algae due to nutrient enrichment

CThe presence of heavy metals in water

DThe formation of oil slicks on water surfaces

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Question 48

jamb 2023

According to the kinetic theory of gases, the pressure exerted by a gas is due to

AThe vibrations of gas particles.

BThe weight of the gas particles

CThe attractive forces between gas particles

DThe collisions of gas particles with the container walls

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Question 49

jamb 2023

What is the sum of the oxidation numbers in a neutral compound?

A+2

B-1

D+1

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Question 50

jamb 2023

Which of the following reactions would be expected to have the highest entropy change?

ALiquid → Gas

BSolid → Liquid

CGas → Liquid

DGas → Solid

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