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Chemistry Past Questions

Study and practice Chemistry past questions with answers and detailed explanations. Then test your knowledge using our interactive CBT practice platform and prepare confidently for your upcoming examinations.

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

2,505 questions
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Question 1 of 20 2,505 total questions
Question 871
jamb 1994
The shape of ammonia molecule is?
Atrigonal planar
Boctahedral
Csquare planar
Dtetrahedral
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Question 872
jamb 1994
The densities of two gases, X and Y, are 0.5 g dm-3 and 2.0 dm-3 respectively.
What is the rate of diffusion of X relative to Y?
A0.1
B0.5
C2.0
D4.0
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Question 873
jamb 1994
For a gas, the relative molecular mass is equal to 2Y. What is Y?
AThe mas of the gas
BThe vapour density of the gas
CThe volume of the gas
DThe temperature of the gas
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Question 874
jamb 1994

To what temperature must a gas 273 K be heated in order to double both its volume and pressure?

A298 K
B546 K
C819 K
D1092 K
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Question 875
jamb 1994

8g CH4 occupies 11.2 dm3 at s.t.p. What volume would 22 g of CH3CH2CH3 occupy under the same condition?

(C = 12, H = 1)

A3.7 dm3
B11.2 dm3
C22.4 dm3
D33.6 dm3
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Question 876
jamb 1994
At the same temperature and pressure, 50 cm3 of nitrogen gas contains the same number of molecules as?
A25 cm3 of methane
B40 cm3 of hydrogen
C50 cm3 of ammonia
D100 cm3 of chlorine
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Question 877
jamb 1994
A pure solid usually melts?
Aover a wide range of temperature
Bover a narrow range of temperature
Cat a lower temperature than the impure one
Dat the same temperature as the impure one
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Question 878
jamb 1994
A mixture of sand, ammonium chloride and sodium chloride is best separated by?
Asublimation followed by addition of water and filteration
Bsublimation followed by addition of water and evaporation
Caddition of water followed by filtration and sublimation
Daddition of water followed by crystallization and sublimation
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Question 879
jamb 1993
The fraction of crude oil used as jet fuel is
Arefinery gas
Bdiesel oil
Ckerosine
Dgasoline
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Question 880
jamb 1993
At 25oC and 1atm, a gas occupies a volume of 1.50dm3. What volume will it occupy at 100oC and 1atm?
A1.88 dm3
B6.00 dm3
C18.80 dm3
D18.80 dm3
E60.00dm3
View Explanation & Discuss
Question 881
jamb 1993

The dissolution of common salt in water is a physical change because

Athe salt can be obtained by crystallization
Bthe salt can be recovered by the evaporation of water
Cheat is not generated during mixing
Dthe solution will not boil at 100oC
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Question 882
jamb 1993
The function of the copper (ll)tetraoxosulphate (IV) in dilute H2SO4 in the figure above is to
Adry the gas
Babsorb phosphine impurity
Cabsorb ethene impurity
Dfrom an acetylide with ethyne
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Question 883
jamb 1993
The IUPAC nomenclature for the compound above is
Adimethlhexane
B3,5 dimethylhexane
C1.1 dmethyl, 3 methylpentane
D2.4 dimethylhexane
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Question 884
jamb 1993

The two functional groups in the above compound are

Aalcohol and amine
Bacid and amine
Caldehyde and acid
Dketone and amine
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Question 885
jamb 1993
In the diagram above, curve X represents the energy profile for a homogeneous gaseous reaction. Which of the following conditions would produce curve Y for the same reaction?
AIncrease in temperature
BIncrease in the concentration of a reactant
CAddition of a catalyst
DIncrease in pressure
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Question 886
jamb 1993

Half-cell reaction. From the data above , it can be deduced that the most powerful reducing agent of the four metals is

ACu
BFe
CBa
DZn
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Question 887
jamb 1993

For which salt in the graph above does the solubility increase most rapidly with rise in temperature?

ACaSO4
BKNO3
CNaCl
DKCl
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Question 888
jamb 1993
Which of the curves above represents the behaviour of 1 mole of an ideal gas?
Al
Bll
Clll
DlV
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Question 889
jamb 1993

A gas that will turn orange potassium heptaoxodichromate (lV) solution to clear green is?

Asulphur (ii) oxide
Bhydrogen sulphide
Csulphide (lV) oxide
Dhydrogen chloride
View Explanation & Discuss
Question 890
jamb 1993
The confirmatory test for alkanoic acids in organic qualitative analysis is the?
Aturning of wet blue litmus paper red
Breaction with alkanols to form esters
Creaction with sodium hydroxide to form salt and water
Dreaction with aqueous Na2COsp3 to liberate a gas which turns lime water milky
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