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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.

150 questions JAMB 2505 WAEC 1623 NECO 168 CUSTOM 10
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Past Questions

150 questions
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Question 1 of 20 150 total questions
Question 21
neco 2009

The following compounds decolorize acidified potassium tetraoxomanganate (VII) solution EXCEPT

AHOCH2 – CH2OH
BH2C –C =C– CH3
CH3C – HC = CH2
DH2C = CH2
EH3C – C =CH
View Explanation & Discuss
Question 22
neco 2009

The percentage composition of a hydrocarbon is 79.2 carbon 20.8 hydrogen. Calculate its empirical formula [H = 1, C = 12]

ACH
BCH3
CCH4
DC2H2
EC2H6
View Explanation & Discuss
Question 23
neco 2009
Which of the following non-metals reacts most readily with metals?
ACarbon
BChlorine
CNitrogen
DPhosphorus
ESulphur
View Explanation & Discuss
Question 24
neco 2009

Compound with the general formula CnH\(_{2n+2}\) belong to the_______ group

Aalkanal
Balkane
Calkanoate
Dalkene
Ealkyne
View Explanation & Discuss
Question 25
neco 2009
The process involved in the decomposition of sugar by an enzyme is called
Adehydration
Besterification
Cfermentation
Dpolymerization
Esaponification
View Explanation & Discuss
Question 26
neco 2009
Which of the following equations is NOT balanced?
ACH4(g) + 202(9) → CO2(g) + 2H2O(g)
BCU(S) + HNO3(aq) → Cu(NO3)2(aq) + 4H2O(I) + NO(g)
C2KCIO3(s) → 2KCI(s)+ 3O2(g)
DNaH(s) + H2O(1) → NaOH(aq) +H2(g)
ENa2SO4(aq) + BaCl2(aq) → BaSO4(s) + 2NaCl(aq)
View Explanation & Discuss
Question 27
neco 2009
A colourless gas with characteristics odour which dissolves in water to form an alkaline solution is
Aammonia
Bcarbon(IV)oxide
Chydrogen chloride
Dsulphur (IV) oxide
Esulphur (VI) oxide
View Explanation & Discuss
Question 28
waec 2009

Which of the following noble gases has electronic structure similar to that of N in NH\(_3\)? [\(^{14}_7\)N]

A2He
B10Ne
C18Ar
D36Kr
View Explanation & Discuss
Question 29
waec 2009
Which of the following elements exhibits the same chemical properties as the atom \(\frac{35}{17}\)X? An element with
Aatomic number 17
Batomic number 18
Cmass number 35
Dmass number 52
View Explanation & Discuss
Question 30
waec 2009
An important medical use of nuclear radiations is
Aactivation analysis
Bcarbon dating
Cradiotherapy
Dtissue regeneration
View Explanation & Discuss
Question 31
waec 2009
The electron configuration of carbon atom in its excited state is [ 6C]
A1s22s 22px12py 1
B1s 2 2s 22px 22pyo
C1s12s22px12py12pz1
D1s 22s12px12py12pz1
View Explanation & Discuss
Question 32
waec 2009

The electron configuration of carbon atom in its excited state is [ 6C]

A1s22s 22px12py 1
B1s 2 2s 22px 22pyo
C1s12s22px12py12pz1
D1s 22s12px12py12pz1
View Explanation & Discuss
Question 33
waec 2009
Which of the following alloys does not contain copper? l. Brass II. Bronze III. Steel
Al only
Bll only
Clll only
Dll and lll only
View Explanation & Discuss
Question 34
waec 2009
The major product in the solvay process is
ANaOH
BNa 2CO 3
CNH 3
DH 2SO4
View Explanation & Discuss
Question 35
waec 2009
A consequence of global warming is
Aair pollution
Bflooding
Cincreased humidity
Dlow rainfall
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Question 36
waec 2009
Dry hydrogen chloride when dissolved in methylbenzene
Aturns blue litmus paper red
Bturns red litmus paper blue
Cdoes not affect litmus paper
Dbleaches litmus paper
View Explanation & Discuss
Question 37
waec 2009
Ethanol reacts with excess acidified K2Cr 2O7 to produce
Aethanal
Bethane
Cethanoic acid
Dethylethanoate
View Explanation & Discuss
Question 38
waec 2009
What is the product of the reaction between propene and 1 mole of hydrogen iodide?
ACH3CHICH3
BCH 3CH2CHI2
CCH 3CH 2CI3
DCH 3CHICH2I
View Explanation & Discuss
Question 39
waec 2009
What is the molecular formula of a compound with empirical CH2O and vapour density of 90? [H = 1, C = 12, O = 16]
AC4H8O 2
BC4H 8O3
CC6H10C5
DC6H12O6
View Explanation & Discuss
Question 40
waec 2009
When protein is heated to a high temperature it undergoes
Acondensation
Bdenaturation
Chydrolysis
Dpolymerization
View Explanation & Discuss
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