Classroom

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.

64 questions JAMB 2505 WAEC 1623 NECO 168 CUSTOM 10

Select subject

Download PHP app Ask a Question Check Syllabus Past Question Videos Topic Video Lessons

Take a test

Custom CBT

Create and set up a CBT environment with your preferred subjects.

JAMB CBT Simulator

Practice JAMB CBT with real UTME past questions in CBT format.

WAEC CBT Practice 2026 Simulator

CB-WASSCE styled past question practice.

NECO CBT Practice 2026 Simulator

SSCE & GCE styled past question practice.

Past Questions

64 questions

Question 1 of 20 64 total questions

Question 11

jamb 2015

A difference between chemical and physical change is that in a chemical change

Aoxygen is consumed

Bheat is supplied

Cthe reversible process occurs

Da new substance is formed

View Explanation & Discuss

Question 12

jamb 2015

The furring of kettles is caused by the presence of what compound in water?

Acalcium tetraoxosulphate (IV)

Bcalcium hydrogentrioxocarbonate (IV)

Ccalcium hydroxide

Dcalcium trioxocarbonate (IV)

View Explanation & Discuss

Question 13

jamb 2015

Which of the following results in the fall of acid rain?

Aoxide of lead

Bparticulate matter

Coxides of sulphur

Dgaseous hydrocarbon

View Explanation & Discuss

Question 14

jamb 2015

Detergents are manufactured with straight hydrocarbon chains, is to make them

Asoluble

Bbiodegradable

Ccheaper

Dfoamy

View Explanation & Discuss

Question 15

jamb 2015

NH_3(g) + HCl_(s) → NH ₄Cl _(s)

The entropy change in the system above is

Apositive

Bzero

Cnegative

Dintermediate

View Explanation & Discuss

Question 16

jamb 2015

When sugar is dissolve in tea, the reaction is accomplished by?

Apositive change

Bnegative entropy change

Cno entropy change

Da minimum entropy change

View Explanation & Discuss

Question 17

jamb 2015

The elements that belong to the third period of periodic table are

ALi, Be, Al and D

BNa, P, O and Cl

CB, C, N, and O

DNa, Mg, S and Ar

View Explanation & Discuss

Question 18

jamb 2015

An oxidation state of Cr in K2Cr2O7

View Explanation & Discuss

Question 19

jamb 2015

A compound contains 40.0% carbon, 6.7% hydrogen and 53.3% oxygen. If the molar mass of the compound is 180, Find the molecular formula [H = 1, C = 12, O = 16)

ACH₂O

BC₃H₆O₃

CC₆H₁₂O₆

DC₆H₁₂O₃

View Explanation & Discuss

Question 20

jamb 2015

What volume of 0.5mldm³ H₂SO₄ will exactly neutralize 20cm³ of 0.1moldm³ NaOH Solution?

A2.0cm³

B5.0cm³

C6.8cm³

D8.3cm³

View Explanation & Discuss

Question 21

jamb 2015

The energy value of petrol can be determined by

ABomb calorimeter

BCatalytic cracker

CFractionating column

DThermometer

View Explanation & Discuss

Question 22

jamb 2015

The basic particles from which matter could be made up of are as follow, except?

ASalt

BAtom

CIon

DMolecule

View Explanation & Discuss

Question 23

jamb 2015

The number of isomers formed by C₆H₁₄ is

View Explanation & Discuss

Question 24

jamb 2015

\(Cu_2S_{(s)}+ O_{2(g)} = 2CU_{(s)} + SO_{2(g)}\).

In the above reaction, the oxidation number of Cu changes from ___ to _______?

A+1 to 0

B0 to +2

C+2 to +1

D0 to +1

View Explanation & Discuss

Question 25

jamb 2015

All these are electromagnetic waves except

AWhite light

BPhoton

CX-ray

DInfrared

View Explanation & Discuss

Question 26

jamb 2015

Which of these radioactive elements is commonly used as a nuclear fuel

Auranium

Bpalladium

Cactium

Dthorium

View Explanation & Discuss

Question 27

jamb 2015

A major source of oxide of nitrogen is from the burning of

Acoal

Bwood

Cfuel

Dchlorofluorocarbons

View Explanation & Discuss

Question 28

jamb 2015

Rare gases are stable because they

Aare monoatomic

Bform ions easily

Chave duplet or octet electronic configuration in the outermost shells in their atoms

Dare volatile gases

View Explanation & Discuss

Question 29

jamb 2015

Which of the following types of alkanols undergo oxidation to produce alkanoic acids.

I. Primary alkanols
II. Secondary alkanols
III. Tertiary alkanols

AI, II and III

BI and II only

CIII only

DI only

View Explanation & Discuss

Question 30

jamb 2015

Hydrogen can be displaced from a hot alkaline solution by

AFe

BCu

CCa

DSn

View Explanation & Discuss

Question Navigator

Current

Chemistry Past Questions

Take a test

Custom CBT

JAMB CBT Simulator

WAEC CBT Practice 2026 Simulator

NECO CBT Practice 2026 Simulator

Past Questions

Question Navigator

MathsFaculty