Chemistry Past Questions

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

89 questions
Question 1 of 20 89 total questions
Question 21
waec 2020

Which of the following pairs of properties of alkali metals decreases down the group?

AFirst ionization energy and reactivity
Bmelting point and atomic radius
CReactivity and electronegativity
DFirst ionization energy and melting point
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Question 22
waec 2020

The high solubility of ethanol in water is due to?

Aits low boiling point.
Bits low freezing point.
Cits covalent nature
Dhydrogen bonding
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Question 23
waec 2020

Equal masses of calcium trioxocarbonate(iv) were added to dilute hydrochloric acid at the temperature specified. Under which of the following conditions would the reaction be slowest?

ACalcium trioxocarbonate ( iv ) chips a 20°C
BCalcIum trioxocarbonate (IV) chips at 40°C
CCalcium trioxocarbonate (IV) powder at 20'C
DCalcium trioxocarbonate (IV) powder at 40'C
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Question 24
waec 2020

What is the mass of silver deposited when 24,125 C of electricity is passed through a solution or silver salt.

[Ag = 108, IF = 96,500 C ]

A432g
B108g
C54g
D27g
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Question 25
waec 2020

What quantity of electrons is lost when one mole of iron (II) ions is oxidized to iron (III) ?

A0 mole
BI mole
C2 moles
D3 moles
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Question 26
waec 2020

Which or the following products could be formed during incomplete combustion of a hydrocarbon.

i.Carbon ii. Hydrogen III. Carbon (Il) oxide

AI only
BI and II only
CI and III only
DII and III only
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Question 27
waec 2020

Which or the following substances is a polypeptide?

AStarch
BGlycogen
CProtein
DFats
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Question 28
waec 2020

 

The IUPAC name of the compound represented by the structure below is ?








 

A2- chloro but-I ,3-diene.
BBut-1,3-chlorodiene.
C2-chloro but-diene.
D3 -chloro but -1.3-diene.
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Question 29
waec 2020

Which of the following substances is an example of a fine chemical?

ASodium hydroxide
BHydrochloric acid
CEthylene
DAmmonia
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Question 30
jamb 2020

To obtain pure carbon(ii)oxide from its mixture with carbon(iv)oxide, the mixture should be?

APassed over heated copper(ii)oxide
BBubbled through water
CBubbled through conc H\(_2\)SO\(_4\)
DBubbled through conc NAOH
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Question 31
jamb 2020

The most important element on the earth's crust is?

ANitrogen
BHydrogen
COxygen
DFluorine
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Question 32
jamb 2020

Aluminum hydroxide is used in the dyeing industry as a?

ADye
BDispersant
CSalt
DMordant
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Question 33
jamb 2020

An electron can be added to a halogen atom to form a halide ion with?

A8 valence electrons
B7 valence electrons
C2 valence electrons
D3 valence electrons
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Question 34
jamb 2020

When a solid substance disappears completely as a gas on heating, the substance is said to have undergone?

ASublimation
BCrystallization
CDistillation
DEvaporation
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Question 35
jamb 2020

When cathode rays are deflected onto the electrode of an electrometer, the instrument becomes?

ABipolar
BNegatively charged
CPositively charged
DNeutral
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Question 36
jamb 2020

The general formula for the Alkanals is?

AR\(_2\)CO
BRCHO
CROH
DRCOOR
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Question 37
jamb 2020

Proteins in acid solution undergo?

ASubstitution
BFermentation
CHydrolysis
DPolymerisation
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Question 38
jamb 2020

What mass of water is produced when 8.0g of hydrogen reacts with excess oxygen?

A8.0g
B16.0g
C36.0g
D72.0g
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Question 39
jamb 2020

The chlorinated alkane often used industrially to remove grease is?

ATetrachloromethane
BChloromethane
CTrichloromethane
DDichloromethane
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Question 40
jamb 2020

The substance often used for vulcanization of rubber is?

AChlorine
BHydrogen peroxide
CSulphur
DTetraoxosulphate(vi) acid
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