JAMB UTME 2020
JAMB Chemistry 2020 past questions
7 objective questions from the 2020 JAMB Chemistry paper. Answer each one, then reveal the answer and explanation.
Question 1
Separation techniquesWhich method separates a mixture of salt and sand?
- Option A: Distillation only
- Option B: Dissolution, filtration, and evaporation
- Option C: Sublimation
- Option D: Chromatography
Show the answerHide the answer to question 1
Answer: B, Dissolution, filtration, and evaporation
Salt dissolves in water, sand is filtered off, and evaporation recovers the salt.
Question 2
Mole conceptHow many moles are there in 392 g of tetraoxosulphate(VI) acid (H₂SO₄)? [H = 1, S = 32, O = 16]
- Option A: 8 mol
- Option B: 2 mol
- Option C: 40 mol
- Option D: 4 mol
Show the answerHide the answer to question 2
Answer: D, 4 mol
Moles = mass ÷ molar mass = 392 ÷ 98 = 4 mol.
Question 3
Electronic configurationWhat is the electronic configuration of oxygen (atomic number 8)?
- Option A: 2, 5
- Option B: 2, 7
- Option C: 2, 6
- Option D: 2, 8
Show the answerHide the answer to question 3
Answer: C, 2, 6
Fill the shells in order, 2 then 8 then 8: oxygen has 8 electrons, arranged 2, 6.
Question 4
Chemical symbolsWhat is the chemical symbol of lead?
- Option A: L
- Option B: Le
- Option C: Pb
- Option D: P
Show the answerHide the answer to question 4
Answer: C, Pb
Lead is Pb, from its Latin name plumbum.
Question 5
Acids, bases and saltsA solution of calcium hydroxide is commonly called
- Option A: brine
- Option B: caustic soda
- Option C: limewater
- Option D: baking soda
Show the answerHide the answer to question 5
Answer: C, limewater
Limewater is aqueous calcium hydroxide.
Question 6
Organic chemistryWhat is the molecular formula of ethane?
- Option A: C₂H₄
- Option B: C₂H₆
- Option C: C₂H₂
- Option D: C₂H₅
Show the answerHide the answer to question 6
Answer: B, C₂H₆
Alkanes follow CₙH₂ₙ₊₂, so ethane with 2 carbon atoms is C₂H₆.
Question 7
Periodic tableIn which group of the periodic table is aluminium found?
- Option A: Group VI
- Option B: Group VII
- Option C: Group 0
- Option D: Group III
Show the answerHide the answer to question 7
Answer: D, Group III
Aluminium (configuration 2, 8, 3) is in Group III.
Practise JAMB 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.
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