How to Pass WAEC Chemistry in 2027: Study Guide

Chemistry sits between Physics and Biology: it has calculations, definitions, drawings and a lot of facts to remember. The students who do well are rarely the ones who memorise the most. They are the ones who understand a few core ideas, practise calculations until they are routine, and treat the practical as a topic in its own right.

This guide gives you a way to study WAEC Chemistry for the 2027 cycle.

What the exam asks of you

Like the other sciences, the chemistry syllabus is assessed through objective and theory questions and includes practical work. The format details (number of questions, marks, duration) are set by WAEC and may be updated, so check the current chemistry syllabus at waecnigeria.org and ask your school which practical arrangement applies to you.

Your preparation should cover four types of demand:

Build the foundation first

Three ideas appear everywhere, so give them your first week.

1. Atomic structure and the periodic table. Know protons, neutrons, electrons, isotopes and electron configuration. Trends down a group and across a period explain a great deal of later chemistry.

2. Bonding. Ionic, covalent and metallic bonding, and the properties each type of bond explains (melting point, conductivity, solubility).

3. The mole. This is the key to stoichiometry. If you can move comfortably between mass, moles, volume of a gas and number of particles, most calculation questions stop being frightening.

Here is an original example to practise.

What mass of calcium carbonate decomposes to give 2.2 g of carbon dioxide? (CaCO₃ → CaO + CO₂; use Ca = 40, C = 12, O = 16.)

• Molar mass of CO₂ = 12 + 32 = 44 g/mol
• Moles of CO₂ = 2.2 / 44 = 0.05 mol
• From the equation, 1 mol CaCO₃ gives 1 mol CO₂, so moles of CaCO₃ = 0.05 mol
• Molar mass of CaCO₃ = 40 + 12 + 48 = 100 g/mol
• Mass = 0.05 × 100 = 5 g

The pattern is always: write the balanced equation, convert to moles, compare ratios, convert back.

Then work through the main blocks

Organic chemistry without panic

Many students treat organic chemistry as a separate subject. It is easier when you learn it as families:

• Alkanes: single bonds, reaction by substitution.
• Alkenes: double bond, addition reactions and a test with bromine water.
• Alkanols, alkanoic acids and esters: functional groups and how they convert.

Practise naming by counting carbons, then add the functional group. Draw structural formulas for the first four members of each series and check them against your textbook.

Qualitative analysis for the practical

The practical often tests how well you can identify ions from observations. Build a table with four columns: the ion, the reagent, the observation and the conclusion. For example, add sodium hydroxide solution drop by drop and then in excess, and note whether a precipitate forms and whether it dissolves. Then add ammonia solution and compare.

A few habits that save marks:

• Record the observation, not your guess. Write "white precipitate, soluble in excess" instead of "it is zinc".
• Use correct terms: precipitate, effervescence, colourless gas, turns damp red litmus blue.
• Never say a solution is "clear" when you mean "colourless"; clear means transparent.

For a step-by-step approach, read our WAEC chemistry practical tips.

A weekly routine that works

1. Two sessions on one topic, using notes and examples.
2. One session of 25 to 30 objective questions on that topic, with a correction in your notebook.
3. One calculation session: four calculations, written fully.
4. One recap session: write the key reactions or definitions from memory.

Use this together with our guide to memorising faster: spaced recall beats rereading. For topic priorities, see WAEC Chemistry topics to focus on.

Mistakes that cost marks

• Not balancing equations before using ratios.
• Forgetting state symbols or conditions when asked to write full equations.
• Mixing up oxidation and reduction (a memory phrase helps: loss of electrons is oxidation, gain of electrons is reduction).
• Leaving off units or significant figures.
• Believing in "expo". It is not a study method, and it risks your result.

Practise now

Chemistry rewards practice more than reading. Use ExamPadi's free WAEC Chemistry questions, switch on the timed CBT mode when you are ready for exam speed, and keep a notebook of every question you miss. The ExamPadi bank holds 46,182 questions across the four exam bodies, is free to start with a Pro tier, and runs on Android, iOS, web and Windows.

Begin at WAEC Chemistry practice, and when you are ready for a broader plan, see how to pass WAEC.