Chemistry Past Questions

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

52 questions
Question 1 of 20 52 total questions
Question 1
jamb 1994

From the above diagram, the caustic soda in the conical flask serves to

Adry ethene gas
Bremove carbon (iv) oxides from ethene
Cremove carbon (ii) oxide from ethene
Dremove sulphur (iv) oxide from ethene
View Explanation & Discuss
Question 2
jamb 1994

When sodium ethanoate is treated with a few drops of concentrated tetraoxosulphate(vi)acid. one of the products is

ACH3COOH
BCH3COOCH3
CCH3COOC2H5
DC2H5COOCH3
View Explanation & Discuss
Question 3
jamb 1994
Clothes should be properly rinsed with water after bleaching because
Athe bleach decolourizes the clothes
Bchlorine reacts with fabrics during bleaching
Cthe clothes are sterilized during bleaching
Dhydrogen chloride solution is produced during bleaching
View Explanation & Discuss
Question 4
jamb 1994

which of these metals CANNOT replace hydrogen from alkaline solutions?

AAluminium
BZinc
CTin
DIron
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Question 5
jamb 1994

MnO4(aq) + 8H + 5Fe2+ \(\to\) Mn2+(aq) + 5Fe3+(aq) + H2O. The oxidation number of maganese in the above reaction changed from

A+7 to +2
B+6 to +2
C+5 to +2
D+4 to +2
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Question 6
jamb 1994

Use the diagram above to answer this question. The reaction taking place in flask G is known as?

Ahydrolysis
Bdouble decomposition
Cdehydration
Dpyrolysis
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Question 7
jamb 1994
The IUPAC name of the compound above is
A2,2-dimethyl but -1-yne
B2,2-dmethyl but -1-ene
C3,3-dimethyl but -1-ene
D3,3-dimethyl but-1-yne
View Explanation & Discuss
Question 8
jamb 1994

In the diagram above, R is a mixture of?

Apotassium tetraxochlorate (VII) and concentrated H2SO4
Bpotassium trioxochlorate (V) and concentrated H2SO4
Cpotassium tetratoxomanganate (VII) and concentrated HCI
Dmanganese (IV) oxide and concentrated HCI
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Question 9
jamb 1994

2HCL(ag) + CaCO3(ag) → CaCL2(ag) + H2O(1) + CO from the reaction above, which of the following curves represents the consumption of calcium trioxocarbonate (IV) as dilute HCL is added to it?

AL
BM
CN
DP
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Question 10
jamb 1994
In the diagram above the activation energy is represented by
Ay - x
Bx
Cx - z
Dy
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Question 11
jamb 1994
The ∆H for the reaction represented by the energy profile above is
A-100 kJ mol--1
B+ 100 kJ mol-1
C+50 kJ mol-1
D-50 kJ mol-1
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Question 12
jamb 1994
The set-up above would be useful for determining the amount of
Aoxygen in air
Bwater vapour in air
CCO2 in air
Darygen in air
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Question 13
jamb 1994

The diagram above represents an atom of

Amagnesium
Bhelium
Cchlorine
Dneon
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Question 14
jamb 1994
Which of the following reagents will confirm the presence of unsaturation in a compound?
AFehling's solution
BBromine water
CTollen's reagent
DBenedict's solution
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Question 15
jamb 1994
One mole of a hydrocarbon contains 48 g of carbon. If it vapour density is 28, the hydrocarbon is?
Aan alkane
Ban alkene
Can alkyne
Daromatic (C = 12, H = 1)
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Question 16
jamb 1994

The general formula of alkanoates is?

ARCHO
BR2CO
CRCOOH
DRCOOR
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Question 17
jamb 1994
When sodium is added to ethanol, the products are?
Asodium hydroxide and water
Bsodium hydroxide and hydrogen
Csodium ethoxide and water
Dsodium ethoxide and hydrogen
View Explanation & Discuss
Question 18
jamb 1994

Which of the following compounds is NOT an isomers of 2,2 dimethylbutane?

A2-methylbutane
B3-methylpentane
C2,3-dimethylbutane
D2-methylpentane
View Explanation & Discuss
Question 19
jamb 1994

Which of the following is the correct order of decreasing activity of the metals Fe, Ca, Al and Na?

AFe> Ca> Al> Na
BNa> Ca> Al> Fe
CAl> Fe> Na> Ca
DCa> Na> Fe>, Al
View Explanation & Discuss
Question 20
jamb 1994
Which of the following is NOT true of metals?
AThey are good conductors of electricity
BThey ionize by electron loss
CTheir oxides are acidic
DThey have high melting points
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