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.

45 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

45 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 45 total questions
Question 11
jamb 1988
Which of the following compounds has the highest boiling point?
ACH3CH2CH2CH2HO
BCH3CH2CH2CHO
CCH3CH2CH2CH3
DCH3CH2OCH2CH3
View Explanation & Discuss
Question 12
jamb 1988
The four classes of hydrocarbons are?
Aethane, ethene, ethyne and benzene
Balkanes, alkenes, alkynes and aromatics
Calkanes, alkenes, alkynes and benzene
Dmethane, ethane , propane and butane
View Explanation & Discuss
Question 13
jamb 1988

Alkanoates are formed by the reaction of alkanoic acid with?

AAlkyl halides
Balkanols
Cethers
Dsodium
View Explanation & Discuss
Question 14
jamb 1988
Methylethanoate reacts with ammonia to yield?
Amettylamine and ethanol
Bethylamine and methanol
Cmethanamide and ethanol
Dethanamide and methanol
View Explanation & Discuss
Question 15
jamb 1988
Crude copper can be purified by the electrolysis of CuSO4(aq) if?
Aplatinum electrodes are used
Bthe crude copper is made the anode of the cell
Cthe crude copper is made the cathode of the cell
Dcrude copper electrodes are used
View Explanation & Discuss
Question 16
jamb 1988
Given the reactions (i) Fe(s) + X(NO3)2(aq) → Fe(NO3) + X(s) (ii) H2(g) + XO
Acopper
Bzinc
Ccalcium
Dlead
View Explanation & Discuss
Question 17
jamb 1988
Aluminium is extracted commercially from its ore by?
Aheating aluminium oxide with coke in a furance
Bthe electrolysis of fused aluminium oxide in cryolite
Ctreating cryolite with sodium hydroxide solution under prressure
Dheating sodium aluminium silicate to a high temperature
View Explanation & Discuss
Question 18
jamb 1988
Chlorine is produced commmercially by?
Aelectrolysis of dilute hydrochloric acid
Belectrolysis of brine
Cneutralization of hydrogen chloride
Dheating potassium trioxochlorate (V)
View Explanation & Discuss
Question 19
jamb 1988
The thermal decomposition of copper (ll)trioxonitrate (V) yields copper (ll) oxide, oxygen and?
Anitrogen (ll) oxide
Bnitrogen (l) oxide
Cnitrogen (lV) oxide
Dnitrogen
View Explanation & Discuss
Question 20
jamb 1988
Suitable reagents for the laboratory preparation nitrogen are?
Asodium dioxonitrate (III) and ammonium chloride
Bsodium dioxonitrate (V) and ammonium chloride
Csodium chloride and ammonium chloride
Dsodium chloride and ammonium diozonitrate (III)
View Explanation & Discuss
Question 21
jamb 1988
When H2S gas is passed into a solution of iron (III) chloride, the colour changes from yellow to green. This is because?
AH(s)S is reduced to S
BFe3+ ions are oxidized by H(s)S
CFe3+ ions are oxidized Fe3+ ions
DFe3+ ions are reduced to Fe2+ ions
View Explanation & Discuss
Question 22
jamb 1988
Which of the following is used in fire extinguishers?
ACarbon (ll) oxide
BCarbon (lV) oxide
CSulphur (lV) oxide
DAmmonia
View Explanation & Discuss
Question 23
jamb 1988
Which property of a reversible reaction is affected by a catalyst?
AHeat content (enthalphy)
BEnergy of activation
CFree energy change
DEquilibrium position
View Explanation & Discuss
Question 24
jamb 1988
Which of the followingstatements is TRUE?
AThe dissolution of NaOH(s) in water is endothermic
BThe heat os solution of NaOH(s) is positive
CThe NaOH(s) gains heat from the surroundings
DThe heat of solution of NaOH(s) is negative
View Explanation & Discuss
Question 25
jamb 1988

Which of the following will produce the greatest increase in the rate of the chemical reaction represented by the equation Na2S2O3(aq) + 2HCl(aq) → 2NaCI(aq) + H2O(I) + SO2(g) + S(g)?

AA decrease in temperature and an increase in the concentration of the reactants
BAn increase in the temperature and a decrease in the cocentration of the reactants
CAn increase in temperature and an increase in the concentration of the reactants
DA decrease in the temperature and a decrease in the concentration of the reactants
View Explanation & Discuss
Question 26
jamb 1988
A mixture of starch solution and potassium iodide was placed in a test tube. On adding dilute tetraoxosulphate (lV) acid and then K2Cr2O7 solutions, a blue-black colour was produced. In this reaction, the?
Aiodide is oxidized
Btetraoxosulphate (Vl) acid acts as an oxidizing agent
Cstarch has been oxidized
DK2Cr2O7 is oxidized
View Explanation & Discuss
Question 27
jamb 1988

Which of the following reactions takes place in the cathode compartment during the electrolysis of copper (II) chloride solution?

ACu2+ + 2e- → Cu(s)
B2Cl- -2e → Cl2
CCu(s) -2e → Cu2+(aq)
DCu2+(aq) + 2Cl-(aq) → CuCl2(aq)
View Explanation & Discuss
Question 28
jamb 1988
Which of the following acts both s a reducing and an oxidizing agent?
AH2
BSO2
CH2S
DC
View Explanation & Discuss
Question 29
jamb 1988
Which of the following substances is a basic salt?
ANa2CO3
BMg(OH)CI
CNaHCO3
DKSO4.AI2(SO4)3,24H2O
View Explanation & Discuss
Question 30
jamb 1988

What volume of a 0.1 M H\(_3\)PO\(_4\) will be required to neutralize 45.0 cm\(^3\) of a 0.2 M NaOH?

A10.0 cm3
B20.0 cm3
C27.0 cm3
D30.0 cm3
View Explanation & Discuss
Question Navigator
Current
MathsFaculty