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.

37 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

37 questions

Question 1 of 17 37 total questions

Question 11

waec 2005

NaHCO_3(s) can be distinguished from Na₂CO_3(s) by the action of

Adilute hydrochloric acid

Bcarbon (IV) oxide

Caqueous ammonia

Dheat

View Explanation & Discuss

Question 12

waec 2005

Which of the following is not an acid anhydride?

AP ₂O ₅

BNO ₂

CSO ₂

DCO

View Explanation & Discuss

Question 13

waec 2005

HNO3 does not usually react with metals to liberate hydrogen because HNO3 is

Aa strong acid

Ba corrosive acid

Can oxidizing agent

Da nitrating agent

View Explanation & Discuss

Question 14

waec 2005

Which of the following statements is not a postulate of the kinetic theory of gases?

AMolecules move with the same speed

Bintermolecular forces are negligible

CMolecules are in a state of constant random motion

Dcollision between molecules is elastic

View Explanation & Discuss

Question 15

waec 2005

When X is heated with manganese (IV) oxide, oxygen is produced X is

AKCI

BKCIO₃

CCaCO₃

DZnCO₃

View Explanation & Discuss

Question 16

waec 2005

Which of the following factors does not affect the rate of reaction of CaCO₃ with HCI?

Atemperature of the reaction

Bsolubility of the CaCO₃

Cconcentration of the HCI

Dsurface area of the CaCO₃

View Explanation & Discuss

Question 17

waec 2005

The activation energy of a reaction can be altered by

Aadding a reducing agent

Bapplying a high pressure

Cusing a catalyst

Dchanging the temperature

View Explanation & Discuss

Question 18

waec 2005

In which of the following reactions is the position of equilibrium not affected by an increase in pressure?

A3Fe_(s) + 4H₂O_(g) ⇌ Fe₃O_4(s) + 4H_2(g)

B2NO_2(g) ⇌ N₂O _4(g)

C3H_2(g) + N_2(g) ⇌ 2NH_3(g)

D2SO_2(g) + O_2(g) ⇌ 2SO_3(g)

View Explanation & Discuss

Question 19

waec 2005

The volume occupied by a given mass of gas depends on its

Adiffusion rate

Btemperature and pressure

Cdegree of solubility

Drelative density

View Explanation & Discuss

Question 20

waec 2005

Which of the following molecules has a linear structure?

ANH₃

BH₂O

CCO₂

DCH₄

View Explanation & Discuss

Question 21

waec 2005

Which of the following can be used to predict the type of bonding in HCI?

ApH value

BElectronegativity difference

CHeat of neutralization

DHeat of solution

View Explanation & Discuss

Question 22

waec 2005

An element which can exist in two or more forms in the same physical state, exhibits

Aisotopy

Bstructural isomerism

Callotropy

Dvariable valency

View Explanation & Discuss

Question 23

waec 2005

An element X has an atomic number of 16. What is its most likely oxidation state in its binary compounds?

A-3

B-2

C+2

D+4

View Explanation & Discuss

Question 24

waec 2005

Which of the following changes is characteristic of an alpha-particle emission?

Athe nucleus loses two protons and two neutrons

Ba proton combines with an electron giving off heat

Cthe nucleus splits into two equal parts

Dfour neutrons are lost

View Explanation & Discuss

Question 25

waec 2005

Which of the following sets of elements are arranged in order of decreasing atomic size in the Periodic Table?

A₆C, ₄Be, ₇N,₈ O

B₄Be,₆ C,₇ N,₈ O

C₈O, ₇ N, ₆C, ₄Be

D₇N, ₈O, ₆C,₄Be

View Explanation & Discuss

Question 26

waec 2005

What is the mass number of an element having 20 neutrons, 15 protons and 15 electrons?

A15

B30

C35

D50

View Explanation & Discuss

Question 27

waec 2005

The electronic configuration of an element X is 1s²2s ²2s⁶3p ² 3p⁴. It can be deduced that X

ABelongs to group 6 of the Periodic Table

BBelongs to group IV of the Periodic Table

Chas 3 unpaired electrons in its atom

Dhas relative molecular mass of 16

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