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.

4,306 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

4,306 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 20 4,306 total questions
Question 1011
waec 2008

If 5.00cm3 of 0.20 mol dm-3Na2CO3 was diluted with distilled water to obtain 250 cm3 solution, what is the concentration of the resulting solution?

A0.004 mol dm-3
B0.02 mol dm-3
C0.20mol dm-3
D0.40mol dm-3
View Explanation & Discuss
Question 1012
waec 2008
Which of the following compounds with the corresponding masses contain the highest percentage of nitrogen? [N = 14]
ANH3 = 17
BNH4CI = 53.5
CNH4NO3 = 80
D(NH3)2SO4 = 132
View Explanation & Discuss
Question 1013
waec 2008
Which of the following compounds with the corresponding masses contain the highest percentage of nitrogen? [N = 14]
ANH3 = 17
BNH4CI = 53.5
CNH4NO3 = 80
D(NH3)2SO4 = 132
View Explanation & Discuss
Question 1014
waec 2008
What is the mass of 6.02 x 1024 atoms of magnesium? [Mg = 24, Avogadro c x 1023 atoms mol-1]
A240g
B24 g
C2.4g
D0.24g
View Explanation & Discuss
Question 1015
waec 2008

The force of attraction between covalent molecules is?

Aelectrostatic attraction
Bhydrogen bonding
Cionic force
Dvan der Waals forces
View Explanation & Discuss
Question 1016
waec 2008
Water molecules are held together by
Acovalent bond
Bhydrogen bond
Cionic forces
Dvan der Waals forces
View Explanation & Discuss
Question 1017
waec 2008
Arrange the following elements in order of increasing electron affinity: Br2CI2
I 2
F 2
AI 2CI2Br2F 2
BI 2Br2CI2F 2
CCI2 I 2Br2F 2
DBr2CI2 I 2 F 2
View Explanation & Discuss
Question 1018
waec 2008
Consider the following elements and their electronic configurations
W: 1s22s2
X: 1s 22s22p6
Y: 1s22s22p63s2
Z: 1s22s22p63s23p2. Which of the elements belong to the same group in the periodic table?
AW and X only
BY and Z only
CW and Y only
DW, Y and Z only
View Explanation & Discuss
Question 1019
waec 2008
Elements in the same group of the periodic table have
Athe same number of valence electrons
Bthe same number of electron shells
Cdifferent chemical behaviour
Dthe same atomic size
View Explanation & Discuss
Question 1020
waec 2008
Which of the following statements is not true of halogens?
Athey exist in different physical states
Bthey exist as diatomic molecules
Ctheir ionic radii decrease down the group
Dtheir melting and bolling points increase down the group
View Explanation & Discuss
Question 1021
waec 2008

Atom \(^{234} _{88} Q\) decay by alpha emission to give an atom R. The atomic number and mass number of atom R are respectively

A86 and 230
B87 and 234
C88 and 233
D90 and 238
View Explanation & Discuss
Question 1022
waec 2008
What is the atomic number of an element whose cation Y+ has the electronic configuration 1s22s22p6?
A9
B10
C11
D12
View Explanation & Discuss
Question 1023
waec 2008
The valence electrons in a chloride ion are [17CI]
A2p electrons only
B3s and 3p electrons only
C3p and 3d electrons only
D3p electrons only
View Explanation & Discuss
Question 1024
waec 2008
Find the number of neutrons in an atom represented by 4521X.
A21
B24
C45
D66
View Explanation & Discuss
Question 1025
waec 2008
The mass spectrometer can be used to measure mass of
Aan atom
Ban electron
Ca proton
Da neutron
View Explanation & Discuss
Question 1026
jamb 2008
Choose the correct option from the structure above
AA
BB
CC
DD
View Explanation & Discuss
Question 1027
jamb 2008

Use the diagram to answer this question.The colour of the fountain water is

Ablue
Borange
Cred
Dyellow
View Explanation & Discuss
Question 1028
jamb 2008

Use the diagram to answer this question. The gas that can be used to demonstrate the experiment is

Ahydrogen chloride
Bhydrogen sulphide
Cnitrogen(ll) oxide
Ddinitrogen (l) oxide
View Explanation & Discuss
Question 1029
jamb 2008

Detergents are manufactured with straight hydrocarbon chains so as to make them

Asoluble
Bbiodegradable
Ccheaper
Dfoamy
View Explanation & Discuss
Question 1030
jamb 2008

Polyvinyl chloride is used in the production of

Aglass
Balloy
Cpipes
Dceramics
View Explanation & Discuss
Question Navigator
Current
MathsFaculty