NECO Likely 2027 — Chemistry questions

50 likely Chemistry questions for the 2027 NECO examination, written from the official syllabus and recurring past-question patterns, each with the correct answer and a short explanation. The first 6 are free to read — full access (₦2,990 once) unlocks all 50.

Unlock all 50 for ₦2,990 Practise Chemistry in CBT mode Chemistry syllabus

1. Which sequence of operations would best separate a mixture of ammonium chloride, sodium chloride and sand?

Separation Techniques

2. Two isotopes of the same element have identical numbers of

Atomic Structure and Isotopy

3. Which of the following Period 3 elements has the largest atomic radius?

Periodic Table and Periodicity

4. Which substance consists of a giant covalent structure?

Chemical Bonding

5. A gas occupies 240 cm³ at 27°C. What volume will it occupy at 127°C if its pressure remains constant?

Gas Laws

6. What mass of pure calcium carbonate is required to produce 5.6 dm³ of carbon dioxide at STP on complete thermal decomposition? [Ca = 40, C = 12, O = 16; molar gas volume at STP = 22.4 dm³]

Mole Concept and Stoichiometry

These are AI predictions for revision, not leaked or official exam questions.