Chemistry Past Questions

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2,505 questions JAMB 2505 WAEC 1623 NECO 168 CUSTOM 10
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Past Questions

2,505 questions
Question 1 of 20 2,505 total questions
Question 621
jamb 2005

The component of an atom that contributes least to its mass is the

Aproton
Bnucleus
Cneutron
Delectron
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Question 622
jamb 2005

Sugar is separated from its impurities by

Aprecipitation
Bcrystallization
Cdistillation
Devaporation
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Question 623
jamb 2005

Which of these properties gives a solid its definite shape?

Astrong intermolecular attraction
Bhigh melting point
Chigh boiling point
Dweak intermolecular attraction
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Question 624
jamb 2005

The shape of the hydrocarbon compound CH\(_4\) is

Asquare planar
Bplanar
Clinear
Dtetrahedral
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Question 625
jamb 2005

How many moles of limestone will be required to produce 5.6g of CaO?
[Ca = 40, C = 12, O= 16]

A0.20 mol
B0.10 mol
C1.12 mol
D0.56 mol
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Question 626
jamb 2005

Natural water collected from rivers and ponds contain oxygen, carbon (IV) oxide and

Anitrogen
Bhydrogen
Cchlorine
Dsulphur
Eoxide
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Question 627
jamb 2005

The gas that is the most dangerous pollutant to human is

Asulphur (IV) oxide
Bcarbon (IV) oxide
Cnitrogen (II) oxide
Dhydrogen sulphide
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Question 628
jamb 2005

Kerosene is commonly used to remove the red colour stain of palm oil from cloths because it

Ahelps to spread the oil over a larger surface area
Breact with the oil to form an odourless compound
Cmakes the oil evaporate easily by dissolving it
Dhelps to dilute the oil and reduce its colour
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Question 629
jamb 2005

The air around smelting industries is likely to contain

AH2S, CO and N2
BCO2, SO3 and H2
CH2, SO2 and CO2
DSO2, N2 and CO2
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Question 630
jamb 2005

The solubility curve shows the variation of solute concentration with

Avolume
Btemperature
Cvapour density
Dpressure
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Question 631
jamb 2005

25cm\(^3\) of a mixture of noble gases was obtained from air after the removal of other constituents. What was the original volume of air?

A2,500 cm3
B1250 cm3
C125 cm3
D80 cm3
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Question 632
jamb 2005

When water boilers are used for long period of time, the solid substances left behind as scale are

Amagnesium trioxosilicate (IV) and rust
Bmagnesium trioxosilicate (IV) and calcium tetraoxosulphate (VI)
Cclay and magnesium troxosulphate (IV)
Dclay and rust
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Question 633
jamb 2005

A substance that is used as a ripening agent for fruits is

Aethene
Bpropene
Cmethane
Dbutane
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Question 634
jamb 2005

Equal moles of ethyne and hydrogen iodide react to give

ACH2 = CH2
BCH2 - CHI
CCH3 - CI
DCH2 = CHI
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Question 635
jamb 2005

How many hydrogen atoms does a single ring cycloalkane have less than the corresponding open-chain alkane?

ATwo
BThree
CFour
DOne
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Question 636
jamb 2005

In the purification of impure samples of ethyl ethanoate synthesized by esterification, concentrated sodium trioxocarbonate (IV) solution is used to remove

Awater
Bbasic impurities
Cacidic impurities
Dethoxyethane
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Question 637
jamb 2005

Which of the following are structural isomers?

Apropanoic acid and propan-1, 2-diol
BPropanal and propanone
CEthanoic acid and propanoic acid
DEthan-1, 2-diol and ethanoic acid
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Question 638
jamb 2005

The decolourization of purple colour of tetraoxomanganate (VII) ion is a test for

Aalkenes
Balkanols
Calkanals
Dalkanes
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Question 639
jamb 2005

The enzymes responsible for converting sucrose into two simple isomeric sugars is

Amaltase
Bamylase
Cinvertase
Dlactase
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Question 640
jamb 2005

What will happen if an aluminium spoon is used to stir a solution of iron (II) trioxonitrates (V)?

AThe spoon will be oxidized while the iron (II) ions will be reduced to the metal
BThe spoon will increase in size
CThe spoon will be reduced while the iron (II) ions will be oxidized
DThe spoon will be reduced
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