Skip to content

WAEC WASSCE 2020

WAEC Chemistry 2020 past questions

7 objective questions from the 2020 WAEC Chemistry paper. Answer each one, then reveal the answer and explanation.

All WAEC Chemistry past questions

  1. Question 1

    Acids and bases

    A solution with a pH of 2 is

    1. Option A: strongly acidic
    2. Option B: weakly acidic
    3. Option C: neutral
    4. Option D: strongly alkaline
    Show the answer to question 1

    Answer: A, strongly acidic

    A pH well below 7 means a strongly acidic solution.

  2. Question 2

    Chemical symbols

    What is the chemical symbol of tin?

    1. Option A: Ti
    2. Option B: Sn
    3. Option C: T
    4. Option D: S
    Show the answer to question 2

    Answer: B, Sn

    Tin is Sn, from its Latin name stannum.

  3. Question 3

    Acids, bases and salts

    Antacid tablets relieve indigestion because they are

    1. Option A: strong acids
    2. Option B: neutral salts
    3. Option C: oxidising agents
    4. Option D: mild bases
    Show the answer to question 3

    Answer: D, mild bases

    Antacids are mild bases that neutralise excess stomach acid.

  4. Question 4

    Electronic configuration

    What is the electronic configuration of nitrogen (atomic number 7)?

    1. Option A: 2, 5
    2. Option B: 2, 4
    3. Option C: 2, 6
    4. Option D: 2, 7
    Show the answer to question 4

    Answer: A, 2, 5

    Fill the shells in order, 2 then 8 then 8: nitrogen has 7 electrons, arranged 2, 5.

  5. Question 5

    Periodic table

    In which group of the periodic table is oxygen found?

    1. Option A: Group VI
    2. Option B: Group II
    3. Option C: Group III
    4. Option D: Group IV
    Show the answer to question 5

    Answer: A, Group VI

    Oxygen (configuration 2, 6) is in Group VI.

  6. Question 6

    Mole concept

    How many moles are there in 351 g of sodium chloride (NaCl)? [Na = 23, Cl = 35.5]

    1. Option A: 6 mol
    2. Option B: 12 mol
    3. Option C: 3 mol
    4. Option D: 60 mol
    Show the answer to question 6

    Answer: A, 6 mol

    Moles = mass ÷ molar mass = 351 ÷ 58.5 = 6 mol.

  7. Question 7

    Organic chemistry

    What is the molecular formula of nonane?

    1. Option A: C₉H₁₈
    2. Option B: C₉H₁₆
    3. Option C: C₉H₁₉
    4. Option D: C₉H₂₀
    Show the answer to question 7

    Answer: D, C₉H₂₀

    Alkanes follow CₙH₂ₙ₊₂, so nonane with 9 carbon atoms is C₉H₂₀.

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