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Chemistry Past Questions

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88 questions JAMB 2505 WAEC 1623 NECO 168 CUSTOM 10

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88 questions

Question 1 of 20 88 total questions

Question 11

jamb 2023

At 2.0 atm pressure, the volume of a gas is 4.0 L. If the pressure is reduced to 1.0 atm while keeping the temperature constant, what will be the new volume of the gas?

A2.0 L

B6.0 L

C8.0 L

D4.0 L

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Question 12

jamb 2023

Which functional group is present in alkanals?

ACarbonyl group (C=O)

BHydroxyl group (-OH)

CAlkyl group (-R)

DCarboxyl group (-COOH)

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Question 13

jamb 2023

What happens when alkanoic acids react with alcohols in the presence of an acid catalyst?

ASaponification

BEsterification

CPolymerization

DHydrolysis

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Question 14

jamb 2023

Which of the following metals is commonly alloyed with copper to make brass?

AIron

BNickel

CAluminum

DZinc

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Question 15

jamb 2023

What is the atomic number of aluminium?

A13

B26

C14

D12

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Question 16

jamb 2023

Which type of salt is found in antacid medications and is used to relieve heartburn and indigestion?

AAluminum chloride

BMagnesium chloride

CSodium chloride

DCalcium chloride

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Question 17

jamb 2023

When anhydrous cobalt chloride paper is exposed to water, what color change is observed?

AFrom pink to blue

BFrom white to blue

CFrom blue to white

DFrom blue to pink

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Question 18

jamb 2023

What is the valency of an element with the electronic configuration 2, 8, 7?

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Question 19

jamb 2023

Which of the following methods is commonly used to remove suspended impurities from water?

AFluoridation

BChlorination

CFiltration

DDistillation

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Question 20

jamb 2023

Which transition metal is known for its multiple colorful oxidation states and compounds used in pigments and paints?

ASilver (Ag)

BCopper (Cu)

CGold (Au)

DZinc (Zn)

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Question 21

jamb 2023

Which element is placed at the top of the electrochemical series?

ACopper

BHydrogen

CSodium

DOxygen

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Question 22

jamb 2023

Isotopes of an element have

AThe same number of protons but different numbers of neutrons.

BThe same number of neutrons and electrons

CThe same number of protons and neutrons

DThe same number of protons and electrons

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Question 23

jamb 2023

What is the molecular geometry of a molecule with three bonding pairs and no lone pairs around the central atom?

ATetrahedral

BTrigonal planar

CLinear

DOctahedral

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Question 24

jamb 2023

At room temperature and standard pressure, chlorine gas is in which state of matter?

APlasma

BSolid

CLiquid

DGas

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Question 25

jamb 2023

Sodium reacts vigorously with water to produce

ASodium chloride (NaCl) and oxygen gas (O2)

BSodium nitrate (NaNO3) and water (H2O)

CSodium hydroxide (NaOH) and hydrogen gas (H2)

DSodium oxide (Na2O) and hydrogen gas (H2)

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Question 26

jamb 2023

Which of the following is a unique property of water compared to other liquids?

AIt is a poor solvent

BIt does not evaporate

CIt expands when freezing

DIt has a low heat capacity

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Question 27

jamb 2023

The contact process is used for the industrial production of

Asulfuric acid (H2SO4)

BHydrochloric acid (HCl)

CSodium hydroxide (NaOH)

DCalcium oxide (CaO)

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Question 28

jamb 2023

If gas A has a molar mass of 32 g/mol and gas B has a molar mass of 64 g/mol, what is the ratio of their diffusion rates?

A2:1

B1:2

C1:1

D1:4

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Question 29

jamb 2023

Which of the following compounds is an example of an electrovalent bond?

ANaCl (sodium chloride)

BCO2 (carbon dioxide)

CH2O (water)

DCH4 (methane)

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Question 30

jamb 2023

A blue litmus paper turns red when dipped into a solution. What does this indicate about the solution?

AThe solution is basic

BThe solution is neutral

CThe solution is acidic

DThe litmus paper is faulty

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