WAEC Chemistry Questions and Answers for 2026 (Theory and

WAEC Chemistry Questions and Answers for 2026 (Theory and Objectives)

Are you looking for WAEC Chemistry Questions and Answers? if your answer is yes, then you are in the right place. The questions below are WAEC past questions and answers that will help you in your WAEC Chemistry 2026 questions.

WAEC Chemistry Questions and Answers

The West African Examinations Council (WAEC) is an examination body in Nigeria that conducts the Senior Secondary Certificate Examination and the General Certificate of Education in May/June and November/December respectively.

WAEC Timetable for May/June Examination

WAEC Chemistry Questions and Answers 2026

The questions below are the WAEC 2026 Chemistry practice questions. Go through them and be ready to score high in your WAEC 2026 Chemistry exam.

1. What condition favors the formation of the product for the endothermic reaction, N2O4(g) —><—– 2NO2(g)

A. Reduction of pressure

B. A decrease in volume

C. An increase in pressure

D. A constant volume

ANSWER: A (Pressure reduction)

2. How many alkoxy alkanes can be obtained from the molecular formula C₄ H₄Oh₄

R.1

B.2

C.3

D.4

ANSWER: C (3)

3. The element Y has two isotopes Y and Y present in a 1:3 ratio. The relative atomic mass of Y would be

A.20.5

B.21

C.21.5

D.22

ANSWER: C (21.5)

4. 100.0 g of KClO₃ was added to 40.0 cm^3 of water to give a saturated solution at 298K. If the solubility of the salt is 20.0 moldm^-3 at 298K, what percentage of the salt remains undissolved? {K=39, Cl=35.5, O=16}

A. 80%

B. 60%

C. 5%

D. 2%

5. Elements X and Y have a 1S electronic configuration²2S²2P⁴ and 1S²2S²2P⁶3S²3P¹ respectively. When they combine, the formula of the compound formed is

A.XY

BY₂X₃

CY₂ X₃

D.YX₂

ANSWER: B (Yes₂X₃)

6. A solution of 0.20 moles of NaBr and 0.20 moles of MgBr₂ in 2.0 dm³ of water must be analyzed. How many moles of Pb(NO₃ )₂ must be added to precipitate all the bromide as insoluble PbBr₂

A. 0.30 moles

B. 0.10 moles

C. 0.20 mole

D. 0.40 moles

ANSWER: A (0.30 mole)

7. No₂CO₃ + HCl —-> NaHCO₃ +NaCl. The most suitable indicator for this reaction should have a pH equal to.

A.3

B.5

C.7

D.9

ANSWER: D (9)

8. A saturated solution of silver(IV) trioxocarbonate was found to have a concentration of 1.30 x 10^-5 mold^-3 . The solubility product of trioxocarbonate (IV) is

R. 8.79 x 10^-15

B. 1.69 x 10^-10

C. 1.82 x 10^-11

D. 9.84 x 10^-10

ANSWER: A (8.79 x 10^-15)

9. When platinum electrodes are used during the electrolysis of a solution of copper(II)(IV) tetraoxosulfate, the solution becomes gradual

A. Acid

B.Basic

C. Neutral

D. Atmospheric

ANSWER: A (acid)

10. Tetraoxosulfate (VI) ions are the final test using

A. acidified silver nitrate

B. acidic barium chloride

C. lime water

D. diluted hydrochloric acid

ANSWER: D (diluted hydrochloric acid)

WAEC Chemistry Theory Questions 2022

ARTICLE 2 (TESTING)

SECTION A

1. Identify the solid remaining when each of the following is heated.
(a) lithium trioxonitrate (V);
(b) potassium trioxonitrate (V);
(c) calcium trioxonitrate (V);

2. (a) When calcium oxide and coke are heated in an electric furnace, the products are carbon oxide (ii) and calcium carbide (CaC2), write the equation for this reaction.

(b) Adding water to calcium carbide leads to the formation of calcium hydroxide and ethyne. Write the equation for the production of ethyne.

3. Calculate the mass percentage of silicon tetrachloride. [2 marks]4. Ammonia, NH3, and phosphine, Ph3, are the hydrides of the first two elements of group 5.
(a) Draw a dot and cross diagram for the ammonia molecule. [2 marks](b) Draw and explain the shape of the ammonia molecule. [3 marks]

5. The first ionization energy of chlorine is +1260KJmol-1.
(a) Define the term first ionization energy.
(b) State and explain the general trend in first ionization energy values ​​for the elements over the period from sodium to argon in the periodic table.

6. Compound A consisting only of carbon and hydrogen. The compound was found to contain 80% carbon by mass.
(a) Calculate the empirical formula for compound A using the data above.
(b) The relative molecular mass of compound A was found to be 30.
Use this information to derive the molecular formula of compound A.
[H = 1.00 C = 12.00]

7. Name two factors other than a change in temperature or the use of a catalyst that influence the rate of a chemical reaction.

SECTION B

1. (a) Two elements represented by the letters Q and R have atomic numbers 9 and 12, respectively.
(i) Write the election configuration of R.
(ii) Which group does Q belong to in the periodic table.
(iii) Write the formula of the compound formed when Q combines with R.
(iv) Briefly explain why Q is a good oxidizing agent.
(v) Indicate whether R should form an acidic or basic oxide.
(b) (i) State two hypotheses of the kinetic theory of gases.
(ii) When some solids are heated, they change directly to the gaseous state. What name do we give to this phenomenon?
(iii) List two substances that exhibit the phenomenon mentioned in (ii).
(iv) Write an expression to show the mathematical relationship between the diffusion rate of a gas and its vapor.

2. An aqueous solution has a pH of 4.0.
(a) (i) What is the concentration of hydrogen ions in the solution?
(ii) What effect will this have on the litmus paper?
(iii) Which of the following salt solutions would have the same effect on sunflower? Give the reason for your answer. NH4Cl(aq); NaCl(aq); CH3OON(aq).
(b) (i) Differentiate between a fine chemical and a heavy chemical.
(ii) Name two sources of air pollution.
(iii) Suggest a way to reduce air pollution in cities

3. (a) (i) Briefly explain the fermentation process.
(ii) Write a balanced equation for the fermentation of glucose.
(iii) What substance should be added to the glucose solution to ferment it?
(iv) Explain briefly why a tightly corked glass, filled to the brim with palm wine, breaks when standing.
(b) Indicate an industrial application for each of the following separation methods:
(i) Crystallization;
(ii) Fractional distillation.
(c) Explain the following terms:
(i) Saponification;
(ii) Esterification.
(d) Write a balanced equation to illustrate each term in (c).
(e) i) What is a hydrocarbon compound?
(ii) Name two main sources of hydrocarbons.

Tips for Passing WAEC Chemistry Questions

Study hard

Everyone knows that hard work leads to success. Make sure you read the chemistry textbooks recommended by the West African Examinations Council (WAEC).

This will help you take a look at most of the questions you will see on the WAEC Chemistry exam day.

Let me make it clear that the questions are not imported from the sky but from those textbooks recommended by WAEC.

Read WAEC Chemistry Past Questions

WAEC usually selects questions from previous years to form new questions. Studying WAEC Chemistry past questions would give you an idea of ​​how WAEC Chemistry questions are set.

If you have any questions about WAEC Chemistry 2026 questions and answers, please drop your question in the comment box and don’t forget to share this information by clicking on the Facebook share icon or any of the social media share icons below.

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