Log In SignUp
Classroom

Chemistry Past Questions

Study and practice Chemistry past questions with answers and detailed explanations. Then test your knowledge using our interactive CBT practice platform and prepare confidently for your upcoming examinations.

35 questions JAMB 2505 WAEC 1623 NECO 168 CUSTOM 10
Download PHP app Ask a Question Check Syllabus Past Question Videos Topic Video Lessons

Take a test

Custom CBT

Create and set up a CBT environment with your preferred subjects.

JAMB CBT Simulator

Practice JAMB CBT with real UTME past questions in CBT format.

WAEC CBT Practice 2026 Simulator

CB-WASSCE styled past question practice.

NECO CBT Practice 2026 Simulator

SSCE & GCE styled past question practice.

Past Questions

35 questions
All JAMB WAEC NECO CUSTOM
All years 2025 2024 2023 2022 2021 2020 2019 2018 2017 2016 2015 2014 2013 2012 2011 2010 2009 2008 2007 2006 2005 2004 2003 2002 2001 2000 1999 1998 1997 1996 1995 1994 1993 1992 1991 1990 1989 1988 1987 1986 1985 1984 1983 1982 1981 1980 1979 1978
Question 1 of 15 35 total questions
Question 11
waec 1991
A compound which liberates carbon (IV) oxide from a hydrogentrioxocarbonate (lV) could have the molecular formula
AC2H5OH
BC 3H 4
CHCOOH
DH2O2
EC6H6
View Explanation & Discuss
Question 12
waec 1991
In which of the following are the substances arranged in their correct order of increasing melting point?
ASodium chloride, sulphur, diamond
BDiamond, sodium chloride, sulphur
CSulphur, sodium chloride, diamond
DDiamond, sulphur, sodium chloride
ESulphur, diamond, sodium chloride
View Explanation & Discuss
Question 13
waec 1991
Which of the following statements is not correct? Group 7 elements
Aare diatomic
Bare good oxidizing agents
Care highly electronegative
Dhave relatively low ionization potentials
Ehave high electron affinity
View Explanation & Discuss
Question 14
waec 1991

Which of the following modes of motion is exhibited by the particles of a solid?

AVibrational and random motion
BVibrational and translational motion
CTranslational and random motion
DVibrational motion only
ETranslational motion only
View Explanation & Discuss
Question 15
waec 1991
The products of the electrolysis of dilute sodium chlorid solution with platinum electrodes are
Ahydrogen and oxygen
Boxygen and chlorine
Cchlorine and water
Dsodium amalgam and chlorine
Esodium hydroxide and water
View Explanation & Discuss
Question 16
waec 1991
Which of the following formula is that of a dicarboxylic acid?
A(CH3CH 2)2CHCOOH
BCH2(OH)2
CCH3CH(OH)COOH
DCH2(COOH)2
ECH3COCOOH
View Explanation & Discuss
Question 17
waec 1991
Brass is an alloy of copper and
Airon
Bchromium
Czinc
Dtin
Emagnesium
View Explanation & Discuss
Question 18
waec 1991
CH2 = CH2 + H2SO4 → CH3 - CH2 -OSO3H. The reaction illustrated by the equation above is an example of
Asubstitution
Boxidation
Creduction
Daddition
Edisplacement
View Explanation & Discuss
Question 19
waec 1991
Which of the following elements can from more than one acidic oxide?
AHydrogen
BSulphur
CCarbon
DAlumium
EIron
View Explanation & Discuss
Question 20
waec 1991

Which of the processes represented by the following equations has the greatest positive entropy change?

AC6H3(l) → C6H 6 (g)
BH2O (s) → H2O(l)
CCuO(s) + H2(g) → Cu(s) + H2
DNa2CO3(s) + nH2O(l) →Na 2CO3nH2O(s)
ES(s) → S(l)
View Explanation & Discuss
Question 21
waec 1991
What is the amount (in mole) of sodium trioxocarbonate (IV) in 5.3 g of the compound? (Na2CO3 = 106)
A0.05
B0.10
C0.20
D0.50
E2.00
View Explanation & Discuss
Question 22
waec 1991
When air is passed through a heated tube containing finely divided copper, the component that is absorbed in the process is
Acarbon (IV) oxide
Bnitrogen
Coxygen
Dwater vapour
Enoble gases
View Explanation & Discuss
Question 23
waec 1991
The separation of a mixture of calcium trioxocarbonate (lV) and sodium trioxocarbonate (IV) is most easily carried out by using the differences in their
Aphysical states
Bmelting points
CRf. values
Dsolubility
Eboiling points
View Explanation & Discuss
Question 24
waec 1991
In which of the following is the oxidation number of nitrogen zero?
ASO2 and NH3
BNaNO3
CHNO2
DNOI3
EN2
View Explanation & Discuss
Question 25
waec 1991
The metal extracted from cassiterite is
Acalcium
Bcopper
Ctin
Dsodium
Elead
View Explanation & Discuss
Question Navigator
Current
MathsFaculty