Chemistry Past Questions

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4,306 questions JAMB 2505 WAEC 1623 NECO 168 CUSTOM 10
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Past Questions

4,306 questions
Question 1 of 20 4,306 total questions
Question 1651
jamb 1994

The diagram above represents an atom of

Amagnesium
Bhelium
Cchlorine
Dneon
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Question 1652
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 1653
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 1654
jamb 1994

The general formula of alkanoates is?

ARCHO
BR2CO
CRCOOH
DRCOOR
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Question 1655
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
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Question 1656
jamb 1994

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

A2-methylbutane
B3-methylpentane
C2,3-dimethylbutane
D2-methylpentane
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Question 1657
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
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Question 1658
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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Question 1659
jamb 1994

In an electrolytic set-up to protect iron from corrosion, the iron is?

Amade cathode
Bmade anode
Cused with a metal of lower electropositive potential
Dinitially coated with tin
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Question 1660
jamb 1994
SO3 is NOT directly dissolved in water in the preparation of H2SO4 by the contact process because?
Athe reaction between SO3 and water is violently exothermic
Bacid is usually added to water and never water to acid
CSO3 does not dissolve in water readily
DSO3 is an acid gas
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Question 1661
jamb 1994

Which of these solutions will give a white precipitate with a solution of barium chloride acidified with hydrochloric acid?

ASodium trioxocarbonate (IV)
BSodium tetraoxosulphate (IV)
CSodium trioxosulphate (IV)
DSodium sulphide
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Question 1662
jamb 1994
Clothes should be properly rinsed with water after bleaching because?
Athe bleach decolourizes the cothes
Bchlorine reacts with fabrics during bleaching
Cthe clothes are sterilized during bleaching
Dhydrogen chloride solution is produced during bleaching
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Question 1663
jamb 1994
Which of these metals CANNOT replace hydrogen from alkaline solutions?
AAlulinium
BZinc
CTin
DIron
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Question 1664
jamb 1994
Which of the following are produced when ammonium trioxonitrate (V) crystals are cautiously heated in a hard glass round bottomed flask?
AN2O and steam
BNO2 and ammonia
CN2O2 and NO2
DNO and NO2
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Question 1665
jamb 1994
Which of the following is TRUE of Le Chatelier's Principle for an exothermic reaction?
AIncrease in temperature will cause an increase in the equilibrium constant
BIncrease in temperature will cause a decrease in the equilibrium constant
CAddition of a catalyst will cause an increase in the equilibrium constant
DAddition of a catalyst will cause a decrease in the equilibrium constant
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Question 1666
jamb 1994
MnO4(aq) + 8H + (aq) + 5Fe2+ → Mn2+(aq) + 4H2O(I). The oxidation number of manganese 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 1667
jamb 1994

An anhydride is an oxide of non-mental

Awhich will not dissolve in water
Bwhose solution in water has a pH greater than 7
Cwhose solution in water has a pH less than 7
Dwhose solution in water has a pH of 7
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Question 1668
jamb 1994
H- + H2(I)O → H2(g) + OH-(aq). From the equation above, it can be inferred that the?
Areaction is a double decomposition
Bhydride ion is a reducing agent
Chydride ion is an oxidizing agent
Dreaction is neutralization
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Question 1669
jamb 1994
Crude copper could be purified by the electrolysis of concentrated copper (II) chloride if the crude copper is?
Amade both the anode and the cathode
Bmade the cathode
Cmade the anode
Ddissolved in the solution
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Question 1670
jamb 1994

What volume of Oxygen measured at s.t.p would be liberated on electrolysis by 9650 coulombs of electricity?
(Molar volume of gas = 22.4 dm\(^3\), 1F = 96,500 C/mol)

A22.4 dm3
B11.2 dm3
C1.12 dm3
D0.560 dm3
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