Chemistry Past Questions

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Past Questions

4,306 questions
Question 1 of 20 4,306 total questions
Question 31
jamb 2025

The fractions of crude oil are best separated by 

Asteam distillation
Bfractional crystallization
Cprecipitation
Dfractional distillation
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Question 32
jamb 2025

The above structure is 

Aalkylamine
Balkanone
Calkanamide
Damino acid
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Question 33
jamb 2025

The disintegration of radioactive phosphorus to silicon follows the first order kinetics with rate constant k\(_1\) = 3.85 x 10\(^{-3}\). Determine the half life of phosphorus.

A8 s
B180 s
C80 s
D100 s
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Question 34
jamb 2025

An importance of solubility is that it

Adetermines the amount of solute that can dissolve in a given amount of solvent
Blowers the vapour pressure of the liquid
Cenables us to know the chemical reactions of the gas with the liquid
Draises the boiling point of liquid
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Question 35
jamb 2025

A table in which metals are arranged in series according to their comparative tendencies to give up their valence electrons is 

Aperiodic table
Belectrochemical series
Ctable of elements
Dperiodicals
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Question 36
jamb 2025

Electron configuration of Chlorine atom is 

A1S\(^2\)2S\(^2\)2P\(^6\)3S\(^2\)3P\(^5\)
B1S\(^2\)2S\(^2\)2P\(^6\)3S\(^2\)3P\(^4\)
C1S\(^2\)2S\(^2\)2P\(^6\)3S\(^2\)3P\(^6\)
D1S\(^2\)2S\(^2\)2P\(^5\)3S\(^2\)3P\(^6\)
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Question 37
jamb 2025

The most suitable indicator to be used when reacting ethanedioic acid with potassium hydroxide is 

Aphenolphthalein
Bmethyl orange
Cmethyl red
Dmethyl purple
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Question 38
jamb 2025

The compound responsible for the pleasant scent of fruits and perfumes belongs to the class of 

Aalkanamide
Balkanone
Calkanal
Dalkanoate
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Question 39
jamb 2025

Na\(_2\)X ⇌  2Na\(^+\)  +  X\(^{2-}\)

The bond between Na and X is likely to be

Adative
Bionic
Cmetallic
Dcovalent
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Question 40
jamb 2025

The compound in which the oxidation state of nitrogen is + 3 is

AN\(_2\)O\(_5\)
BN\(_2\)O\(_3\)
CN\(_2\)O\(_4\)
DN\(_2\)O
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Question 41
jamb 2025

An inflated balloon shrinks when placed in a freezer because the 

Avolume of gas increases and expands
Bnumber of gas molecules decreases
Cgas motion reduces and exert less pressure
Dgas molecules completely stop moving
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Question 42
jamb 2025

The constituents of permalloy are Iron and 

ANickel
BTin
CChromium
DCopper
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Question 43
jamb 2025

Magnesium tetraoxosulphate(VI) salt is commonly used as a

Adisinfectant
Bplasticizer
Cfertilizer
Dlaxative
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Question 44
jamb 2025

Anti-freeze used in a vehicle radiator is a mixture of water and

Apropanetriol
Bpropanol
Cpropanone
Dpropanal
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Question 45
jamb 2025

(CH\(_3\))\(_2\)CHCH(OH)CH\(_2\)C(CH\(_3\))\(_3\)

The IUPAC name of the compound above is

A2,5,5-trimethylhexan-3-ol
B1,1-dimethylisopentanol
C1,1,4,4-pentamethylbutanol
D2,5-dimethylhexan-4-ol
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Question 46
jamb 2025

In oxidation reactions, electrons are

Ahydrolysed
Bremoved
Cadded
Dhydrated
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Question 47
jamb 2025

What is the function of concentrated H\(_2\)SO\(_4\)?

AIt reacts with metals to give a salt and hydro gas
BIt is a dehydrating agent
CIt neutralizes alkali
DIt produces a cryolite precipitate with basic solution
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Question 48
jamb 2025

Calculate the time required to liberate 9g of Aluminium metal, when a current of 18A is passed through it.

(1F = 96500C , Al = 27)

A1769.17 minutes
B89.34 minutes
C5360.58 minutes
D29.48 minutes
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Question 49
jamb 2025

Commercial deodorant is an example of a colloid called

Aaerosol
Bsol
Cfoam
Demulsion
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Question 50
jamb 2025

The relative molecular mass of an alkanoic acid with the empirical formula of CH\(_2\)O is

[ H = 1, C = 12, O = 16 ]

A46
B88
C60
D72
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