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 2051
jamb 1982
In the chemical reaction A + B \(\to\) C + D, more of D is formed?
Aif the concentrated of A is reduced
Bif the concentrated of B is reduced
Cif the concentrated of C is reduced
Dif the concentration of C is increased
Eif D is continuously removed from the reaction mixture
View Explanation & Discuss
Question 2052
jamb 1982

In the reaction N2(g) + O(g)
↔ 2NO(g) produced i an increase in the total pressure will?

Acause less nitrogen to be produced in the equilibrium mixture
Bcause less nitric oxide to be produced in the equilibrium mixture
Ccause more nitric oxide to be produced in the equilibrium mixture
Dcause more oxygen to be produced in the equilibrium mixture
Ehave no effect
View Explanation & Discuss
Question 2053
jamb 1982

Which of the following CANNOT be obtained by fractional distillation of petroleum?

AEther
BMethane
CButane
DEthene
EHydrogen
View Explanation & Discuss
Question 2054
jamb 1982

In the reaction NH3 + H+ → NH4+, the bond formed results from?

Aan electron transferred from NH3 + H+
Ban electron pair donated by NH3
Can electron pair equally shared
Dan electron pair donated by H+
Ean electron tarnsferred from H+ to NH3
View Explanation & Discuss
Question 2055
jamb 1982
Which of the following statements is incorrect?
ACalcium reacts with water to form calcium
BMagnesium reacts very slowly with water but faster with warm water
CIron will not react with water in the absence of air
DSodium reacts with water
ECopper reacts with steam
View Explanation & Discuss
Question 2056
jamb 1982
Sodium carbonate crystals on exposure to a dry atmosphere change to a white powder. This phenomenon is known as?
Adeliquescence
Bhygroscopy
Coxidation
Defforescence
Esublimation
View Explanation & Discuss
Question 2057
jamb 1982

The product formed at the the cathode during the electrolysis of sodium chloride solution with carbon electrodes is?

Asodium
Bchlorine
Chydrogen
Dsodium hydroxide
Eoxygen
View Explanation & Discuss
Question 2058
jamb 1982

Which of the following types of reactions takes place between C2H6 and the halogens?

ASubstitution
BPolymerization
CAddition
DSaponification
EOxidation
View Explanation & Discuss
Question 2059
jamb 1982
Cotton is almost pure?
Astarch
Bprotein
Canimal fibre
Dcelluose
Emineral fibre
View Explanation & Discuss
Question 2060
jamb 1982
Water is poured over a white solid and a colourless neutral gas is evolved which burns with a sooty flame. The white solid is?
Acalcium
Bcalcium oxide
Ccalcium carbide
Dsodium peroxide
Esodium sulphate
View Explanation & Discuss
Question 2061
jamb 1982
An amphoteric oxide is an?
Aamorphous oxide of a metal
Bamorphous oxide of a non-mental
Coxide that is insoluble in water
Doxide that behaves both as a base as well as an acid
Eoxide that loses its oxygen on sublimation
View Explanation & Discuss
Question 2062
jamb 1982
Which of the following statements is correct during the electrolysis of a caustic soda solution using platinum electrodes?
AOxygen gas is given off at the cathode
BHydrogen gas is given of at the anode
CSodium metals is deposited at the anode
DSodium metal is deposited at the cathode
EAAlkalinity at the cathode increases
View Explanation & Discuss
Question 2063
jamb 1982
An acid is said to be weak if?
Aits ions are so completely dissociated that they easily drift apart
Bthe acid is not corrosive
Cthe acid has low specific gravity
Dits ions move very slowly when in solution
Eits ions are incompletely dissociated
View Explanation & Discuss
Question 2064
jamb 1981
Which of the following represents a precipitation reaction?
AH2SO4 + NaCl \(\to\) NaHSO4 + HCl
BFe +H2SO4 \(\to\) FeSO4 + H2
C4HCl + MnO2 \(\to\) MnCl2 + 2H2O + Cl2
DNa2SO4 + pb(NO3) \(\to\) PbSO4 + 2NaNO
ECuO +2HCl \(\to\) Cl2 + H2O
View Explanation & Discuss
Question 2065
jamb 1981

The IUPAC name for

A1-methlpentane
B3-methylbutane
C2-methylbutane
D1-dimethylpropane
E2-methylpentane
View Explanation & Discuss
Question 2066
jamb 1981
The general formula of an alkyl halide (which represent the halide) is?
ACnH2n - 2X
BCnH2n + 1X
CCnH2n + 2X
DCnH2nX
ECnH2n - 1
View Explanation & Discuss
Question 2067
jamb 1981

An efflorescent compound is a substance that?

Aabsorbs water froom the air without dissolving in it
Bis capable of giving off coloured luminosity
Cgives out water to the atmosphere
Dabsorbs water from the air and dissolves in it
Egives out its water of crystallization on heating
View Explanation & Discuss
Question 2068
jamb 1981
The scale formation in a kinetic used for boiling water is caused by the presence in water of?
Acalcium sulphate
Bcalcium carbonate
Ccalcium hydrogen carbonate
Dcalcium hydroxide
Emagnesium sulphate
View Explanation & Discuss
Question 2069
jamb 1981

What happens when the nitrates of potassium, calcium, zinc and copper are separately heated?

AAll the nitrate will decompose to their respective metals
BThe nitrates of calcium and potassium will decomposes to their nitrites
COnly copper nitrate decomposes to the metal
DOnly the nitrates of zinc and copper will decompose to their oxides
EThe nitrates of calcium, zinc and copper decompose to their oxides
View Explanation & Discuss
Question 2070
jamb 1981
4g each of aluminium foil and aluminium powder were introduced respectively into flasks P and Q.
Flask P was treated with warm bench sodium hydroxide and all the aluminium dissolved in one hour. Flask Q was treated with cold sodium hydroxide and all the aluminium dissolved in 10 minutes. What was responsible for Q reacting faster than P?
AThere were more aluminium atoms in Q than P
BThe heat given off in retarded the reaction
CQ generated more pressure than P during the reaction
DP generated more pressure than Q
EQ has a greater surface area for the reaction than P
View Explanation & Discuss
Question Navigator
Current
MathsFaculty