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.

4,306 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

4,306 questions

Question 1 of 20 4,306 total questions

Question 1981

jamb 1985

Complete hydrogenation of ethyne yields?

Abenzene

Bmethane

Cethane

Dethene

Epropane

View Explanation & Discuss

Question 1982

jamb 1985

In the reaction H2(g)O \(\to\) H2(g) + 1/2O2(g)

ΔH = -2436000 KJ, which of the following has no effect on the equilibrium position?

AAdding argon to the system

BLowering the temperature

CAdding hydrogen to the system

DDecreasing the pressure

EIncreasing the temperature

View Explanation & Discuss

Question 1983

jamb 1985

Which of the following metals will displace iron from a solution of iron(ll)tetraoxosulphate(lV)?

ACopper

BMercury

CSilver

DZinc

EGold

View Explanation & Discuss

Question 1984

jamb 1985

2MnO^-₄ + 10Cl^- + 16H⁺ → 2Mn²⁺ + 5Cl₂ + 8H₂O. Which of the substances serves as an oxidizing agent?

AMn²⁺

BCl^-

CH₂O

DMnO^-₄

ECl₂

View Explanation & Discuss

Question 1985

jamb 1985

A certain industrial process is represented by the chemical equation 2A_(g) + B_(g) \(\to\) C_(g) + 3D_(g) \(\Delta\)H = X kJmol^-1. Which of the following conditions will favour the yield of the products?

Aincrease in temperature, decrease in pressure

Bincrease in temperature, increase in pressure

Cdecrease in temperature,increase in pressure

Ddecrease in temperature, decrease in pressure

Econstant in temperature, increase in pressure

View Explanation & Discuss

Question 1986

jamb 1985

A correct electrochemical series can be obtained from K, Na, Ca, Al, Mg, Zn, Fe, Pb, H, Cu, Hg, Ag, Au by interchanging?

AAl and Mg

BZn and Fe

CZn and Pb

DPb and H

EAu and Hg

View Explanation & Discuss

Question 1987

jamb 1985

If the ONLY pollutants found in the atmosphere over a city are oxides of nitrogen, suspended lead compounds. carbon monoxide and high levels of methane, the probable source(s) of the pollution must be?

Aautomobile exhaust and biological decomposition

Bcombustion of coal and automobile exhaust

Cbiological decomposition only

Dcombustion of coal, automobile exhaust and biological decomposition

Ecombustion of coal and biological decomposition

View Explanation & Discuss

Question 1988

jamb 1985

What is the formula of sodium gallate if gallium (Ga)shows an oxidation number of + 3?

ANaGaO₃

BNa₂Ga(OH)₃

CNaGa(OH)₃

DNaGa(OH)₄

ENaGaO

View Explanation & Discuss

Question 1989

jamb 1985

X + Y = Z is an equilibrium reaction. The addition of a catalyst?

Aincrease the amount of Z produced in a given time

Bincreases the rate of change in concentrations of X, Y and Z

Cincreases the rate of disapearance of X and Y

Dincreases the rate of the forward reaction

Edecreases the amounts of X and Y left after the attainment of equilibrium

View Explanation & Discuss

Question 1990

jamb 1984

The I.U.P.A.C name for the compound is

Aisopropylethene

Bacetylene

C3- methylbutane

D2-methylbutane

E5-methylpentane

View Explanation & Discuss

Question 1991

jamb 1984

Use the diagram above to answer this question
Which of the following structural formula is NOT isomeric with the others?

View Explanation & Discuss

Question 1992

jamb 1984

USE THE DIAGRAM ABOVE TO ANSWER THIS QUESTION.
Which of the following represents a carboxylic acid?

View Explanation & Discuss

Question 1993

jamb 1984

The name of the compound above is

Aacetic acid

Bpropanal

Cpropanol

Dethanoic acid

Epropanoic acid

View Explanation & Discuss

Question 1994

jamb 1984

The diagram above (Fig.3) shows the energy profile for the reaction A + B + = C + D From this diagram, it is clear that the reaction is

Aspontaneous

Bisothermal

Cadiabatic

Dexothermic

Eendothermic

View Explanation & Discuss

Question 1995

jamb 1984

Which of the curves shown in the figure given represents the relationships between the volume(V) and pressure(P) of an ideal gas at constant temperature

E1 and 3

View Explanation & Discuss

Question 1996

jamb 1984

The solubility curves of four substances are shown in the figure above. Which of the four substances would crystallize from a saturated solution cooled from 353K(80^oC)to 323K(50C)?

AP and Q

BP and R

CP and S

DR and S

EQ and R

View Explanation & Discuss

Question 1997

jamb 1984

At S. T. P how many litres of hydrogen can be obtained from the reaction of 500 cm\(^3\) of 0.5 M H\(_2\)SO\(_4\) with excess zinc metal?
(Gram molecular volume of H\(_2\) = 22.4 dm\(^3\))

A22.4 dm ³

B11 . 2 dm ³

C6. 5 dm ³

D5. 6 dm ³

E0. 00 dm ³

View Explanation & Discuss

Question 1998

jamb 1984

An aqueous solution of a metal salt, M, gives a white precipitate with NaOH which dissolves in excess NaOH. With aqueous ammonia, the solution of M also gives a white precipitate which dissolves in excess ammonia. Therefore cartion in M is

AZn ⁺⁺

BCa⁺⁺

CAi⁺⁺⁺

DPb⁺⁺

ECu⁺⁺

View Explanation & Discuss

Question 1999

jamb 1984

Which of the following electrodes is used in electrolysis of bauxite (Al₂O₃) in molten cryolite?

ASteel electrodes

BCarbon electrodes

CMercury electrodes

DCarbon anode and steel cathode

ECarbon cathode and stell anode

View Explanation & Discuss

Question 2000

jamb 1984

A piece of sea shell, when dropped into a dilute solution of hydrochloric acid, produces a colourless, odourless gas which turns clear limewater milky. The sea shell contains

Asodium chloride

Bammonium nitrate

Ccalcium carbonate

Dcalcium chloride

Emagnesium chloride

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