Chemistry JAMB Questions and Answers 2025 [Revealed!]

This is for UTME Candidates looking for JAMB Chemistry Questions and Answers 2025. Especially for those aspiring for Medicine, Pharmacy and other Health Science courses, including Engineering and Physical Sciences aspirants. Here you will get genuine Chemistry JAMB questions and answers for 2025. Your duty now is to read through them as many times as possible and get ready to smash your Chemistry paper. Remember to use the comments sections if you have questions, and don’t forget to join our Free Online Tutorial Classes on Facebook.

What are JAMB Chemistry Questions and Answers 2025

JAMB Chemistry Questions and Answers 2025 are the questions you should expect in your Chemistry paper in 2025 UTME, together with their answers.

It is very important that every candidate preparing to sit for Chemistry in the forthcoming 2025 JAMB UTME examination should catch a glimpse of these questions.

In so doing, they will know what to expect in the JAMB CBT hall. Knowing exactly what to expect will boost their confidence and guarantee them a very high score.

JAMB Chemistry Questions and Answers 2025 Revealed!

On this page, we shall reveal JAMB Chemistry Questions and Answers 2025 for all candidates taking the Chemistry paper.

How lucky you are to stumble upon this important page!

The questions are genuine and the answers are accurate, and all are a product of our passion to see you excel in your JAMB and gain admission into your dream institution.

In the following sections, you will read the Chemistry questions you are to expect in your 2025 JAMB exam as well as their answers. You can use the comments section if you still need clarification over some of the questions. We will give you a more detailed explanation.

JAMB is a very serious examination and a lot depend on it. You will answer 40 questions in JAMB Chemistry 2025 within 26 minutes. So it’s important that you pay attention to the information revealed on this page.

JAMB Chemistry Questions and Answers 2025 [Numbers 1 – 10]

1. Which of the following is a mixture?
A. Sodium chloride
B. Sea water
C. Iron filings
D. Granulated sugar

2. Two elements, X and Y, have atomic numbers 8 and 13 respectively. The formula for the possible compound found between X and Y is
A. Y₂X₃          B. XY₂
C. X₃Y₂          D. X₂Y₃

3. 3 g of a mixture of CaO and CaCO₃ was heated to a constant mass. If 0.44 g of CO₂ was liberated, calculate the percentage of CaO in the mixture.
A. 33.3%             B. 50%
C. 66.67%           D. 25%

4. An alkanoic acid has a molecular mass of 88. Its molecular formula is
A. C₄H₉COOH       B. C₅H₁₁COOH
C. C₃H₅COOH       D. C₃H₇COOH

5. If the rate of diffusion of oxygen is taken as 1 cm³s^-1, what will be the rate of diffusion of methane whose relative molecular mass is 16?
A. 2.0         B. 1.8
C. 1.4         D. 1.0

6. An increase in temperature causes an increase in the pressure of a gas in a fixed volume due to an increase in the
A. Number of molecules of the gas
B. Density of the gas molecules
C. Number of collisions between the gas molecules
D. Number of collisions between the gas molecules and the walls of the container

7. In electrolysis, the chemical reaction which takes place at the anode is
A. dissociation       B. hydrolysis
C. oxidation           D. reduction

8. In the electrolysis of brine, it is essential to prevent the mixing of the products because
A. sodium and chlorine readily combine
B. chlorine gives a green coloration
C. chlorine readily recombines with sodium hydroxide
D. sodium hydroxide forms a carbonate in the presence of air and chlorine

9. In what way is equilibrium constant for the forward reaction related to that of the reverse reaction?
A. The two equilibrium constants are identical
B. The product of the two is always greater than one
C. The product of the two is expected to be one
D. The addition of the two is expected to be one

10. When chlorine water is exposed to sunlight, the gas evolved is
A. Cl₂          B. O₂
C. HCl         D. CO₂

Answers to Chemistry Question Number 1 – 10

1.B     2.A     3.C     4.D     5.C
6.D     7.C     8.D     9.C     10.B

JAMB Chemistry Questions and Answers 2025 [Numbers 11 – 20]

11. A mixture of iron and sulphur can be separated by dissolving the mixture in
A. Steam
B. Dilute hydrochloric acid
C. Dilute sodium hydroxide
D. Benzene

12. If 67.5 g of oxide of lead was reduced to 61.2 g of metal, calculate the formula of the oxide. (Pb = 207, O = 16)
A. PbO           B. PbO₃
C. Pb₃O₄        D. Pb₂O₃

13. Calculate the minimum volume of the oxygen that is required for complete combustion of a mixture of 20cm³ of CO and 10cm³ of hydrogen.
A. 5cm³          B. 10cm³
C. 15cm³        D. 20cm³

14. HNO₃ + H₂O ↔ H₃O⁺ + NO^3-
In the reaction above, NO^3- is the
A. Conjugate acid       B. Acid
C. Conjugate base      D. Base

15. The pH range of a neutralization product of CH₃COOH and KOH is
A. 1 – 3          B. 7 – 8
C. 6 – 7          D. 12 – 14

16. How much NaOH is required to make 250cm³ of 0.1 mol/dm³ solution?
A. 10 g        B. 1.0 g
C. 0.1 g        D. 4 g

17. 2PbO₂ → 2PbO + O₂
In the equation above, the oxidizing agent is
A. Pb⁴⁺       B. Pb²⁺
C. O^2-          D. O₂

18. A current of 0.5 A flows for 1930 seconds and deposits 0.325 g of metal M. If the charge is +2, the relative molecular mass is
A. 65 g         B. 32 g
C. 24 g         D. 40 g

19. Emission of chlorofluorocarbon (CFC) into the atmosphere causes
A. global warming
B. acid rain
C. depletion of ozone layer
D. greenhouse effect

20. Which of the following samples will react fastest with dilute HCl?
A. 10 g of lumps of CaCO₃ at 25 °C
B. 10 g of powdered CaCO₃ at 25 °C
C. 10 g of lumps of CaCO₃ at 50 °C
D. 10 g of powdered CaCO₃ at 50 °C

Answers to Chemistry Question Number 11 – 20

11.C      12.A      13.C      14.C      15.D
16.B      17.A      18.A      19.C      20.D

JAMB Chemistry Questions and Answers 2025 [Numbers 21 – 30]

21. Two immiscible liquids with different boiling points can be separated by
A. the use of separating funnel
B. evaporation
C. distillation
D. decantation

22. A mixture of CaCl₂ and CaCO₃ in water can be separated by
A. evaporation     B. sublimation
C. distillation        D. decantation

23. Consider the reaction represented by
xPb(NO₃)₂ → 2PbO + yNO₂ + zO₂
What are the values of x, y and z respectively?
A. 2, 6, 3         B. 1, 4, 2
C. 2, 4, 1         D. 2, 4, 2

24. 20 cm³ of H₂ mixed and separated with 100 cm³ of air containing 21% O₂. Calculate the volume of the residual gases at 110 °C.
A. 31 cm³         B. 11 cm³
C. 90 cm³         D. 110 cm³

25. What is responsible for metallic bonding?
A. Sharing of electrons between the metal atoms
B. Attraction between the atomic nuclei and the cloud of electrons
C. Transfer of electrons from one atom to another
D. Attraction between positive and negative ions

26. 25 cm³ of 1.5 M solution of NaCl are added to 50 cm³ 0f 3 M NaCl. The molar concentration of the resulting solution is
A. 2.5 M            B. 3 M
C. 2.25 M          D. 4.5 M

27. A solution of salt formed from HCl and NH₃ solutions is
A. acidic             B. basic
C. complex         D. neutral

28. Which of the following elements will burn in excess oxygen to form a product that is neutral to litmus?
A. Carbon          B. Hydrogen
C. Sulphur          D. Sodium

29. A current was passed for 10 mins and 0.2 mole of Cu was deposited. How many grammes of Ag will it deposit?
(Cu = 64, Ag = 108)
A. 43.2 g           B. 21.6 g
C. 10.8 g           D. 5.4 g

30. Pollution of underground water by metal ions is very likely in a soil that has high
A. acidity
B. alkalinity
C. chloride content
D. nitrate content

Answers to Chemistry Question Number 21 – 30

21.A     22.D     23.C     24.D     25.B
26.A     27.A     28.B     29.A     30.D

JAMB Chemistry Questions and Answers 2025 [Numbers 31 – 40]

31. Elements P, Q and R have atomic numbers 9, 16 and 20 respectively. Which of them would gain electron(s) during ionic bonding?
A. Q and R      B. P and R
C. P and Q      D. P, Q and R

32. Which of the following has the lowest pH?
A. 5cm³ of M/10 HCl
B. 10cm³ of M/10 HCl
C. 20cm³ of M/8 HCl
D. 15cm³ of M/2 HCl

33. Which of the following is an acid salt?
A. (NH₄)₂CO₃      B. CHCOONa
C. KHSO₄            D. MgSO₄.7H₂O

34. CrO^2-₇ + 14H⁺ + 6I → 2Cr³⁺ + 3I₂ + 7H₂O
The change in the oxidation number of oxygen in the equation above is
A. 0         B. 1
C. 2         D. 7

35. During the electrolysis of CuSO₄ solution using Platinum electrodes, which of the following occurs?
A. Acidity increases at the cathode
B. Oxygen is liberated at the cathode
C. pH decreases at the cathode
D. pH of solution decreases

36. Which of the following ions is a pollution in drinking water even in trace quantities?
A. Ca²⁺           B. Pb²⁺
C. Mg²⁺          D. Fe²⁺

37. The solubility of a salt of molar mass 100g at 20°C is 0.34mol/dm³. If 3.4g of that salt dissolved completely in 250cm³ of water at that temperature, the resulting solution is
A. A suspension
B. Saturated
C. Unsaturated
D. Supersaturated

38. Catalyst is important in chemical industry in that
A. It affects the purity of the products
B. It affects the quantity of the products
C. It increases the time for reaching equilibrium
D. Bond breaking is slowed down

39. An alkanoic acid has a molecular mass of 88. Name the acid. (C = 12, O = 16, H = 1)
A. Propanoic acid
B. Botanic acid
C. Pentatonic acid
D. But-2-ionic acid

40. Ethyne undergoes the following reactions except
A. Polymerization
B. Addition
C. Substitution
D. Etherification

Answers to Chemistry Question Number 31 – 40

31.C     32.D     33.C     34.A    35.D
36.B     37.C     38.C     39.A     40.D

Read Also: 20 Most Repeated Topics in JAMB Chemistry Exams 2025

Conclusion

So here you have the 40 Chemistry Questions you can expect to see in your 2025 JAMB examination. Read them again and again. Ensure that you get very familiar with each of them to the extent that you can readily recognize them any time.

Remember that you can ask for more detailed explanation to any of the above questions in case you don’t fully understand it. Don’t be shy, just scroll down and use the comments section. Drop your questions and expect comprehensive answers as soon as possible.

More so, you can help us to reach others with this post by sharing it with friends on Social Media. Just scroll down to see the Facebook and Twitter and WhatsApp buttons. Thank you so much!

See you on the next article.

Read Also: Check Your JAMB Result on this Portal