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.

168 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

168 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 20 168 total questions
Question 31
neco 2008
A chemical system is at equilibrium when
Aδ G is positive
Bδ G is zero
Cδ S is negative
Dδ S is positive
Eδ S is zero.
View Explanation & Discuss
Question 32
neco 2008
When sodium hydroxide solution is added to a solution of zinc salt, the white precipitate formed re-dissolve in excess sodium hydroxide because
Asodium hydroxide is a strong alkali
Bsodium is more reactive than zinc
Czinc is more reactive than sodium
Dzinc hydroxide is amphoteric
Ezinc hydroxide is unstable
View Explanation & Discuss
Question 33
neco 2008
The gas in air used by plants for photosynthesis is
AArgon
BCarbon (IV) oxide
CNitrogen
DOxygen
EWater vapour.
View Explanation & Discuss
Question 34
neco 2008
Which of these arrangement of elements is in order of increasing ionization energy?
ABoron, Carbon, Flourine, Nitrogen
BBoron, Carbon, Nitrogen, Flourine
CCarbon, Boron, Nitrogen, Flourine
DFlourine, Nitro9en, Carbon, Boron
ENitrogen, Flourine, Carbon, Boron
View Explanation & Discuss
Question 35
neco 2008
The following acids are monobasic EXCEPT
Adioxonitrate (Ill) acid
Bethanedioic acid
Chydrobromic acid
Dmethanoic acid
Eoxochlorate (I) acid
View Explanation & Discuss
Question 36
neco 2008

An element Z has a combining power of 3. Which of the following formulae is correct of its compound?

AZS3
BZSO3
CZS04
DZ203
EZ3Cl2
View Explanation & Discuss
Question 37
neco 2008
Bauxite is the ore of
Aaluminium
Bcalcium
CIron
Dsodium
Emagnesium
View Explanation & Discuss
Question 38
neco 2008
Matter is neither created nor destroyed in the course of any chemical reactions is a statement of the law of
Acombining volumes
Bconservation of mass
Cdefinite proportion
Dmultiple proportion
Ereciprocal proportion.
View Explanation & Discuss
Question 39
neco 2008
pH is define as
A[H+]
B–log [H]
C–log [H+]
Dlog [H]
Elog [H+]
View Explanation & Discuss
Question 40
neco 2008
Which of the following compounds is unsaturated?
ACyclohexane
BMethoxyethane
C1 ,2-dibromoethane
D2,2,3-trimethylpentane
E3-methylbut-l-ene
View Explanation & Discuss
Question 41
neco 2008
A solution is prepared by dissolving I .96g of H2SO4 in 250 cm3 of its solution. What is the concentration in moles per dm3?
A0.008
B0.08
C0.1
D0.8
E8.02
View Explanation & Discuss
Question 42
neco 2008
The action of zinc on an acid produces
Achlorine
Bhydrogen
Cnitrogen
Dsulphur
Ewater vapour.
View Explanation & Discuss
Question 43
neco 2008

The high boiling point of hydrogen fluoride can be explained in terms of?

Acovalent bonds.
Bdative bonds.
Cdipole-dipole bonds
Delectrovalent (ionic) bonds.
Ehydrogen bonds.
View Explanation & Discuss
Question 44
neco 2008

What type of bond holds hydrogen fluoride molecules together when forming larger aggregate?

ACovalent
BDative
CHydrogen
DIonic
EMetallic
View Explanation & Discuss
Question 45
neco 2008
A device used in the laboratory for intermittent production of gases without heating is
Aaspirator
Bdelivery tube
Cfume cupboard
Dkipp’s apparatus
Emuller counter
View Explanation & Discuss
Question 46
neco 2008

If two metallic ions of the same concentration migrate to a graphite cathode, the one that would be preferentially discharged is that with the

Agreater stability in solution
Blower electrical charge
Csmaller mass
Dstronger tendency to accept electrons
Estronger tendency to lose electrons.
View Explanation & Discuss
Question 47
neco 2008
The planet with the highest number of moon is
AEarth
BJupiter
CUranus
DPluto
EVenus.
View Explanation & Discuss
Question 48
neco 2008
Pipe-borne water is usually chlorinated in order to
Acoagulate sediments in the water
Bimprove taste of the water
Ckill harmful bacteria in the water
Dmake it pure
Eremove the hardness in the water
View Explanation & Discuss
Question 49
neco 2008
The rate of a chemical reaction is NOT affected by one of these factors
Acolour
Bconcentration
Cpresence of light
Dsurface area
Etemperature
View Explanation & Discuss
Question 50
neco 2008

The molecular formula of ethylbutanoate is?

ACH5COOC26
BC3HCOOC2H7
CC3H7COOC3H7
DC3H7COOC4H9
EC3H7COOC2H5
View Explanation & Discuss
Question Navigator
Current
MathsFaculty