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.

2,505 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

2,505 questions

Question 1 of 20 2,505 total questions

Question 741

jamb 2000

The refreshing and characteristic taste of soda water and other soft drinks is as a result of the presence in them of

Acarbon (IV) oxide

Bcarbon (II) oxide

Csoda

Dglucose

View Explanation & Discuss

Question 742

jamb 2000

A gas that is not associated with global warming is

ACO₂

BSO₃

CCH₄

DH₂

View Explanation & Discuss

Question 743

jamb 2000

The substance often used for vulcanization of rubber is

Achlorine

Bhydrogen peroxide

Csulphur

Dtetraoxosulphate (IV) acid

View Explanation & Discuss

Question 744

jamb 2000

A phenomenon where an element exist in different forms in the same physical state is known as

Aisomerism

Bamorphism

Callotropy

Disotopy

View Explanation & Discuss

Question 745

jamb 2000

For a reaction in equilibrium, the species involved in the equilibrium constant expression are

Agaseous and solid species

Bliquid and solid species

Csolid and dissolved species

Dgaseous and dissolved species

View Explanation & Discuss

Question 746

jamb 2000

N2(g) + O2(g) ↔ 2NO(g); ΔH = + 180.6 kJ mol-1
In the reaction above, increase in temperature will

Aincrease the quantity of N₂

Bincrease in the yield of NO

Cdecrease the yield of NO

Ddecrease the quantity of O₂

View Explanation & Discuss

Question 747

jamb 2000

Powdered marble reacts faster with hydrochloric acid solution than the granular form because the powdered form has

Amore molecules

Bmore atoms

Clarger surface area

Drelatively large mass

View Explanation & Discuss

Question 748

jamb 2000

0.46g of ethanol when burned raised the temperature of 50g of water by 14.3K. Calculate the heat of combustion of ethanol.
[C = 12, O = 16, H = 1, Specific heat capacity of water = 4.2 jg-1K-1]

A+3000 KJ mol^-1

B+300 KJ mol^-1

C-300 KJ mol^-1

D-3000 KJ mol^-1

View Explanation & Discuss

Question 749

jamb 2000

Given that M is the mass of substance deposited in an electrolysis and Q the quantity of electricity consumed, then Faraday's law can be written as

AM = Z/Q

BM = Q/Z

CM = Z/2Q

DM = QZ

View Explanation & Discuss

Question 750

jamb 2000

\(\frac{1}{2}\)Zn\(^{2+}\)(aq) + e\(^-\) → \(\frac{1}{2}\) Zn(s)
In the reaction above, calculate the quantity of electricity required to discharge zinc.
[F = 96 500 C mol\(^{-1}\)]

A0.965 x 10⁴C

B4.820 x 10⁴C

C9.650 x 10⁴C

D48.200 x 10⁴C

View Explanation & Discuss

Question 751

jamb 2000

MnO\(_{4(aq)}^{-1}\) + 8H\(^+ _{(aq)}\) + Y → Mn\(^{2+} _{(aq)}\) + 4H\(_2\)O\(_{(l)}\)
Y in the equation above represents

A2e^-

B3e^-

C5e^-

D7e^-

View Explanation & Discuss

Question 752

jamb 2000

The pOH of a solution of 0.25 mol dm\(^{-3}\) of hydrochloric acid is

A12.40

B13.40

C14.40

D14.60

View Explanation & Discuss

Question 753

jamb 2000

In which order are the following salts sensitive to light?

AAgl > AgCl > AgBr

BAgCl > Agl > AgBr

CAgBr > AgCl > Agl

DAgCl > AgBr > Agl

View Explanation & Discuss

Question 754

jamb 2000

HCl(aq) + H\(_2\)O(l) → H\(_3\)O+(aq) + Cl\(^-\)(aq)
In the reaction above, Cl\(^-\)(aq) is the

Aconjugate acid

Bacid

Cconjugate base

Dbase

View Explanation & Discuss

Question 755

jamb 2000

Hydration of ions in solution is associated with

Aabsorption of heat

Breduction of heat

Cconduction of heat

Dliberation of heat

View Explanation & Discuss

Question 756

jamb 2000

1.0 dm3 of distilled water was used to wash 2.0g of a precipitate of AgCl. If the solubility product of AgCl is 2.0 x 10\({^-10}\)moldm-6, what quantity of silver was lost in the process?

A2.029 * 10^-3mol dm^-3

B1.414 * 10^-3mol dm^-3

C2.029 * 10^-5mol dm^-3

D1.414 * 10^-5mol dm^-3

View Explanation & Discuss

Question 757

jamb 2000

The air pollutant unknown in nature is

ANO

BCO

CHCHO

DDDT

View Explanation & Discuss

Question 758

jamb 2000

Water molecule can be ligands especially when they are bonded to

Aalkaline earth metals

Balkali metals

Ctransition metals

Dgroup VII elements

View Explanation & Discuss

Question 759

jamb 2000

A side effect of soft water is that

Ait gives offensive taste

Bexcess calcium is precipitated

Cit attacks lead contained in pipes

Dit encourages the growth of bacteria

View Explanation & Discuss

Question 760

jamb 2000

The noble gas, argon,is used for

Aelectric arc welding

Bwelding brass

Cunderwater welding

Dsteel welding

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