Are you preparing for WAEC and looking for Chemistry past questions for 2025? If you’ve been asking questions like “Where can I get WAEC Chemistry past questions?”, “What topics should I focus on?”, or “How are the questions structured?”, then this guide is for you. West African Examinations Council Chemistry is one of the core science subjects that requires both theoretical understanding and problem-solving skills. Practicing past questions will help you understand the exam pattern and improve your chances of success. In this article, you will see sample WAEC Chemistry past questions for 2025, including both objective and theory sections.
About WAEC Chemistry
WAEC Chemistry focuses on:
- Atomic structure and bonding
- Acids, bases, and salts
- Organic chemistry
- Chemical reactions and equations
- Periodic table and properties of elements
The exam is divided into Objective (OBJ), Theory, and sometimes Practical/Alternative to Practical sections.
WAEC Chemistry Objective Questions (40 Questions)
Choose the correct answer from options A–D.
- Which of the following is a pure substance?
A. Air
B. Salt
C. Soil
D. Smoke
Answer: B - The smallest unit of an element is
A. Molecule
B. Atom
C. Ion
D. Compound
Answer: B - Which of the following is a chemical change?
A. Melting ice
B. Boiling water
C. Rusting of iron
D. Dissolving sugar
Answer: C - The pH of a neutral solution is
A. 0
B. 7
C. 14
D. 1
Answer: B - Which gas is used in photosynthesis?
A. Oxygen
B. Carbon dioxide
C. Nitrogen
D. Hydrogen
Answer: B - Which of the following is an acid?
A. NaOH
B. HCl
C. NaCl
D. KOH
Answer: B - Which of the following is a base?
A. HCl
B. NaOH
C. H₂SO₄
D. HNO₃
Answer: B - The process of heating a substance strongly without air is called
A. Distillation
B. Sublimation
C. Calcination
D. Evaporation
Answer: C - Which of the following is an element?
A. Water
B. Oxygen
C. Salt
D. Sugar
Answer: B - Which of the following is a compound?
A. Iron
B. Oxygen
C. Water
D. Nitrogen
Answer: C - Which metal reacts with water to produce hydrogen gas?
A. Copper
B. Sodium
C. Gold
D. Silver
Answer: B - Which of the following is a physical change?
A. Burning wood
B. Rusting
C. Boiling water
D. Digestion
Answer: C - The atomic number represents the number of
A. Neutrons
B. Protons
C. Electrons only
D. Nucleons
Answer: B - Which of the following is an example of a mixture?
A. Salt
B. Air
C. Water
D. Oxygen
Answer: B - Which gas turns limewater milky?
A. Oxygen
B. Hydrogen
C. Carbon dioxide
D. Nitrogen
Answer: C - Which of the following is used as an indicator?
A. Litmus
B. Salt
C. Sugar
D. Water
Answer: A - The valency of sodium is
A. 1
B. 2
C. 3
D. 4
Answer: A - Which of the following is an alkali?
A. HCl
B. NaOH
C. CO₂
D. SO₂
Answer: B - Which of the following is a non-metal?
A. Iron
B. Copper
C. Oxygen
D. Zinc
Answer: C - Which of the following is a metal?
A. Oxygen
B. Nitrogen
C. Iron
D. Chlorine
Answer: C - Which of the following is used in electrolysis?
A. Battery
B. Heat
C. Pressure
D. Light
Answer: A - Which gas is produced when an acid reacts with a metal?
A. Oxygen
B. Hydrogen
C. Nitrogen
D. Carbon dioxide
Answer: B - Which of the following is a salt?
A. HCl
B. NaOH
C. NaCl
D. H₂SO₄
Answer: C - Which of the following is an organic compound?
A. NaCl
B. CO₂
C. CH₄
D. H₂O
Answer: C - The boiling point of water is
A. 50°C
B. 100°C
C. 150°C
D. 0°C
Answer: B - Which process separates liquids with different boiling points?
A. Filtration
B. Distillation
C. Evaporation
D. Sublimation
Answer: B - Which of the following is a noble gas?
A. Oxygen
B. Nitrogen
C. Helium
D. Hydrogen
Answer: C - Which of the following is a greenhouse gas?
A. Oxygen
B. Nitrogen
C. Carbon dioxide
D. Hydrogen
Answer: C - Which of the following is a halogen?
A. Sodium
B. Chlorine
C. Calcium
D. Iron
Answer: B - Which of the following is used in making fertilizers?
A. Nitrogen
B. Oxygen
C. Helium
D. Neon
Answer: A - Which of the following is a reducing agent?
A. Oxygen
B. Hydrogen
C. Nitrogen
D. Carbon dioxide
Answer: B - Which of the following is an oxidizing agent?
A. Hydrogen
B. Oxygen
C. Nitrogen
D. Methane
Answer: B - Which of the following is an example of an exothermic reaction?
A. Melting
B. Freezing
C. Combustion
D. Evaporation
Answer: C - Which of the following is an example of an endothermic reaction?
A. Combustion
B. Freezing
C. Photosynthesis
D. Respiration
Answer: C - Which of the following is a catalyst?
A. Iron in Haber process
B. Water
C. Oxygen
D. Nitrogen
Answer: A - Which of the following is used in making glass?
A. Sand
B. Clay
C. Wood
D. Plastic
Answer: A - Which of the following is an electrolyte?
A. Sugar solution
B. Salt solution
C. Oil
D. Alcohol
Answer: B - Which of the following is a strong acid?
A. HCl
B. CH₃COOH
C. NH₃
D. NaOH
Answer: A - Which of the following is a weak acid?
A. H₂SO₄
B. HCl
C. CH₃COOH
D. HNO₃
Answer: C - Which of the following is a neutral substance?
A. HCl
B. NaOH
C. NaCl
D. H₂SO₄
Answer: C
WAEC Chemistry Theory Questions 2025
Answer all questions.
Question 1
(a) Define the following terms:
(i) Atom
(ii) Molecule
(b) State two differences between a physical change and a chemical change.
(c) Give two examples each of:
(i) Elements
(ii) Compounds
Question 2
(a) What is an acid?
(b) State three properties of acids.
(c) Write balanced chemical equations for the reaction between:
(i) Hydrochloric acid and sodium hydroxide
(ii) Sulphuric acid and zinc
(d) State two uses of acids.
Question 3
(a) Explain the structure of an atom.
(b) Complete the table below:
| Particle | Charge | Location |
|---|---|---|
| Proton | ||
| Electron | ||
| Neutron |
(c) Define atomic number and mass number.
(d) State the relationship between atomic number and number of electrons in a neutral atom.
Question 4
(a) What is electrolysis?
(b) State Faraday’s first law of electrolysis.
(c) Name two substances that can be used as electrolytes.
(d) List two uses of electrolysis in industry.
Question 5
(a) Define oxidation and reduction.
(b) Identify the oxidizing and reducing agents in the reaction below:
Zn + Cu²⁺ → Zn²⁺ + Cu
(c) State two examples of oxidation reactions in everyday life.
(d) Explain the term corrosion and state two methods of preventing it.
Question 6
(a) What is organic chemistry?
(b) State two characteristics of organic compounds.
(c) Give the general formula of alkanes.
(d) Write the structural formula of methane and ethane.
Question 7
(a) Define the term mole.
(b) Calculate the molar mass of H₂SO₄.
(c) State Avogadro’s number.
(d) Calculate the number of moles in 44g of CO₂.
Question 8
(a) What is a catalyst?
(b) State two characteristics of a catalyst.
(c) Give two examples of catalysts and their uses.
(d) Explain the Haber process.
How to Use WAEC Past Questions Effectively
To succeed in WAEC Chemistry:
- Practice past questions regularly
- Focus on key topics like acids, bases, and calculations
- Understand formulas and equations
- Time yourself while practicing
- Revise weak areas
Important Information
- WAEC questions are often repeated in different forms
- Understanding concepts is better than cramming
- Calculations are very important in Chemistry
- Always balance chemical equations correctly
Conclusion
Practicing WAEC Chemistry past questions for 2025 is one of the most effective ways to prepare for the exam. It not only helps you understand the question pattern but also exposes you to commonly repeated topics and areas of focus.
By solving past questions regularly, you improve your speed, accuracy, and confidence, especially when dealing with calculations and chemical equations. It also helps you identify your weak areas early so you can revise them properly before the exam.
To achieve the best results, combine past questions with consistent study, proper understanding of concepts, and regular revision. With the right preparation, passing WAEC Chemistry becomes much easier and more achievable.
Frequently Asked Questions (FAQs)
Are WAEC Chemistry questions repeated?
Yes, West African Examinations Council often repeats questions, but they may be reworded or slightly modified. This means practicing past questions helps you become familiar with common topics, question patterns, and how questions are likely to be framed in the exam.
Is Chemistry practical compulsory?
Yes, the practical (or alternative to practical) is compulsory. It tests your understanding of experiments, observations, calculations, and proper handling of laboratory equipment. Preparing well for this section is very important because it contributes significantly to your overall score.
How can I pass WAEC Chemistry?
To pass WAEC Chemistry, you need to study consistently, practice calculations, and understand key topics like chemical equations, acids and bases, organic chemistry, and the periodic table. Regular revision, solving past questions, and timing yourself during practice will greatly improve your performance.
How many papers are in WAEC Chemistry?
There are usually three papers: Objective (multiple choice), Theory (written answers), and Practical (or alternative to practical). You need to perform well in all sections because each contributes to your final grade.
Where can I get more past questions?
You can get WAEC Chemistry past questions from textbooks, your teachers, tutorial centres, and trusted educational websites. Using updated and reliable materials ensures you are practicing with questions that reflect the current exam format and syllabus.
