How to Pass JAMB Chemistry in 2027

Chemistry looks like three subjects stuck together: physical (calculations and rates), inorganic (elements and their reactions), and organic (carbon compounds). Students who treat it as one long list of facts struggle. Students who treat it as three skills, each with its own habit, do far better.

This guide is for the 2027 cycle. It shows the habit for each skill, includes original worked examples, and ends with a plan you can follow.

Know the format

Chemistry is a chosen subject, often paired with Biology (for health sciences) or Physics and Mathematics (for engineering). It carries 40 questions in the computer-based UTME, and the overall time limit is in the official brochure at jamb.gov.ng. Check that Chemistry is part of the subject combination for your course using the JAMB subject combination guide.

Skill one: physical chemistry is a calculation skill

The topics in ExamPadi's Chemistry practice include Stoichiometry, Acids, Bases and Salts, and Electrolysis. All three reward the same routine:

1. Write the balanced equation.
2. Convert given masses to moles.
3. Use the mole ratio from the equation.
4. Convert back to the unit asked for.

An original example:

What mass of NaOH is present in 0.25 mol? (Na = 23, O = 16, H = 1). Molar mass of NaOH = 23 + 16 + 1 = 40 g/mol. Mass = 0.25 × 40 = 10 g.

Hydrogen reacts with oxygen to form water: 2H₂ + O₂ → 2H₂O. How many moles of water form from 4 mol of hydrogen? The ratio of H₂ to H₂O is 2:2, so 4 mol gives 4 mol.

25 cm³ of a 0.2 mol/dm³ solution is diluted to 100 cm³. The new concentration is: use C₁V₁ = C₂V₂, so 0.2 × 25 = C₂ × 100, giving C₂ = 0.05 mol/dm³.

Learn the common atomic masses of H, C, N, O, Na, Mg, Al, S, Cl, K and Ca so that you are not hunting for them. Always confirm the given values in the question first, and use them even if they differ slightly from the ones you memorised.

Skill two: inorganic chemistry is a pattern skill

Do not memorise elements one by one. Learn the periodic table in blocks:

Trend questions repeat. If a question asks about ionisation energy, ask: does it increase across a period? Yes, because the nuclear charge grows and the atomic radius shrinks. Then check the group direction.

Chemical bonding is a similar pattern. Ionic bonds form between metals and non-metals by electron transfer; covalent bonds form between non-metals by sharing; metallic bonds explain conductivity. Link each bond type to its properties (melting point, conductivity in solution) and many questions answer themselves.

Learn the tests for common gases and ions in a small table. A single page of tests (for hydrogen, oxygen, carbon dioxide, ammonia, chlorine, and the common cations and anions) covers a regular question type.

Skill three: organic chemistry is a naming and reaction skill

The key is to learn the families once.

A quick example: An alkane with four carbon atoms has the formula: use CₙH₂ₙ₊₂ with n = 4, giving C₄H₁₀, which is butane.

For naming, count the longest chain, assign the prefix (meth-, eth-, prop-, but-, pent-), then add the suffix for the family (-ane, -ene, -yne, -ol, -oic acid). Practise ten names a day for a week and it becomes automatic.

Polymers, hydrocarbons and industrial chemistry are other topics in this area. For polymers, remember the difference between addition and condensation polymerisation, with one standard example each. For industrial chemistry, learn the basic processes in outline and the raw materials they use.

Environmental chemistry and general knowledge

Environmental Chemistry rewards reading, not calculation. Know the main pollutants, their sources and their effects (for example, acid rain from sulphur dioxide and nitrogen oxides), the ozone layer, and water treatment steps. These are easy marks if you give an hour to them.

Avoid these mistakes

1. Forgetting to balance the equation before using mole ratios.
2. Using grams in a formula that needs moles.
3. Confusing oxidation (loss of electrons) with reduction (gain of electrons).
4. Mixing up the anode and cathode in electrolysis: oxidation happens at the anode.
5. Choosing an answer because it "sounds chemical" without checking. On screen, test each option against the question and strike out the ones with an unbalanced formula, a wrong charge or an impossible unit first.

A six-week plan

Spend part of every session on past questions so that you learn how a topic is asked, not only what it says. The JAMB Chemistry topics to focus on guide shows where to put extra effort. Practical-style questions about apparatus and observations also appear; our WAEC Chemistry practical tips are a useful companion even if you are writing only JAMB.

Practise on screen

ExamPadi offers free JAMB Chemistry practice with explanations and a timed CBT mode. Start with the 2025 JAMB Chemistry past questions and record your accuracy per topic. We cannot promise a particular score, but a record like that shows you what to fix. Tonight, pick one of the three skills, work ten questions, and note why each wrong answer was wrong.