Skip to content

WAEC WASSCE 2018

WAEC Chemistry 2018 past questions

6 objective questions from the 2018 WAEC Chemistry paper. Answer each one, then reveal the answer and explanation.

All WAEC Chemistry past questions

  1. Question 1

    Gas laws

    A fixed mass of gas occupies 780 cm³ at a pressure of 3 atm. What volume will it occupy at 9 atm if the temperature stays constant?

    1. Option A: 2340 cm³
    2. Option B: 780 cm³
    3. Option C: 21060 cm³
    4. Option D: 260 cm³
    Show the answer to question 1

    Answer: D, 260 cm³

    By Boyle's law, P₁V₁ = P₂V₂, so V₂ = 3 × 780 ÷ 9 = 260 cm³.

  2. Question 2

    Acids, bases and salts

    Which salt forms when sodium hydroxide reacts with hydrochloric acid?

    1. Option A: Sodium tetraoxosulphate(VI)
    2. Option B: Sodium trioxonitrate(V)
    3. Option C: Sodium trioxocarbonate(IV)
    4. Option D: Sodium chloride
    Show the answer to question 2

    Answer: D, Sodium chloride

    NaOH + HCl → NaCl + H₂O.

  3. Question 3

    Periodic table

    In which group of the periodic table is magnesium found?

    1. Option A: Group II
    2. Option B: Group VI
    3. Option C: Group VII
    4. Option D: Group 0
    Show the answer to question 3

    Answer: A, Group II

    Magnesium (configuration 2, 8, 2) is in Group II.

  4. Question 4

    Chemical symbols

    What is the chemical symbol of copper?

    1. Option A: C
    2. Option B: Co
    3. Option C: Cr
    4. Option D: Cu
    Show the answer to question 4

    Answer: D, Cu

    Copper is Cu, from its Latin name cuprum.

  5. Question 5

    Atomic structure

    An atom of helium has atomic number 2 and mass number 4. How many neutrons are in its nucleus?

    1. Option A: 4
    2. Option B: 6
    3. Option C: 2
    4. Option D: 3
    Show the answer to question 5

    Answer: C, 2

    Neutrons = mass number − atomic number = 4 − 2 = 2.

  6. Question 6

    Mole concept

    How many moles are there in 18 g of water (H₂O)? [H = 1, O = 16]

    1. Option A: 2 mol
    2. Option B: 1 mol
    3. Option C: 0.5 mol
    4. Option D: 10 mol
    Show the answer to question 6

    Answer: B, 1 mol

    Moles = mass ÷ molar mass = 18 ÷ 18 = 1 mol.

Practise WAEC Chemistry on SchoolEasy CBT

In SchoolEasy, students answer timed questions on screen, see an explanation for every answer, and track their progress topic by topic. Teachers turn past questions into class tests that mark themselves.

Practise in the appRequest a demo for your school

School management made effortless.

We strive to build the best school management software for schools from all over the world.

Available soon on all digital platforms

Download on theApp StoreGet it onGoogle Play