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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.

1,623 questions JAMB 2505 WAEC 1623 NECO 168 CUSTOM 10
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Past Questions

1,623 questions
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Question 1 of 20 1,623 total questions
Question 671
waec 1996
Amphoteric oxides are oxides which
Areact with water to form acids
Breact with water to form alkali
Cshow neither acid nor basic properties
Dreact with acids alkalis
Econtain high proportion of oxygen
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Question 672
waec 1996
Which of the following equations represents a neutralization reaction?
ACaCI2 + 2HCI →CI2 +CaCI 2 + H2O
BNa2O2 + H2SO4 → Na2SO4 + H2O2
CH2SO4 + KOH → KHSO4 + H2 O
D2Na + 2H2O → 2NaOH + H2
ECuSO4 + 2NaOH → Cu(OH)2+ Na2SO4
View Explanation & Discuss
Question 673
waec 1996
A solution of pH 7 is
Aacidic
Bneutral
Cconcentrated
Ddilute
Esaturated
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Question 674
waec 1996

What volume of carbon (lV) oxide is produced at s.t.p. when 2.5g of CaCO3 reacts with excess acid according to the following equation? CaCO3 + 2HCI → CaCI2 +H2O + CO2 [CaCO3 = 100; molar volume of a gas at s.t.p = 22.4dm3]

A11.20dm3
B5.60dm3
C2.24dm3
D0.56dm3
E0.28dm3
View Explanation & Discuss
Question 675
waec 1996
''Equal volumes of all gases at the same temperature and pressure contain the same number of molecules'' is an expression of
ACharles Law
BBoyle's Law
CAvogadro's Law
DGraham's Law
EGay Lussac's Law
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Question 676
waec 1996
What is the likely formula of compound formed between element M in group two and element X in group seven?
AM7X2
BM2X
CM2X7
DMX2
EMX6
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Question 677
waec 1996
The alkali metals exhibit similar chemical properties because
Athey occur in the combined state
Bthey have the same number of vallence electrons
Cthey form crystalline salts
Dtheir salts are soluble in water
Ethey are highly reactive
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Question 678
waec 1996

When an atom gains an electron, it becomes 

Achemically inactive
Bnegatively charged
Coxidized
Da cation
Ea complex ion
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Question 679
waec 1996
The existance of two or more forms of the same element in the same physical state is known as
Aallotropy
Bresonance
Chybridization
Disotopy
Eisomerism
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Question 680
waec 1995
What is the amount (in mole) of hydrogen gas that would be produced if 0.6 mole of hydrochloric acid reacted with excess zinc according to the following equation? Zn(s) + 2HCI(aq) → ZnCI2(aq) + H2(g)
A0.1 mole
B0.2mole
C0.3 mole
D1.0 mole
E2.9 moles
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Question 681
waec 1995
What is the amount (in mole) of hydrogen gas that would be produced if 0.6 mole of hydrochloric acid reacted with excess zinc according to the following equation? Zn(s) + 2HCI(aq) → ZnCI2(aq) + H2(g)
A0.1 mole
B0.2mole
C0.3 mole
D1.0 mole
E2.9 moles
View Explanation & Discuss
Question 682
waec 1995
The following salts dissolve readily in cold water except
ACaCI2
BPbSO4
C(NH4)2SO4
DNa2CO3
ENa2SO3
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Question 683
waec 1995
Copper (ll) tetraoxosulphate (VI) is often added to swimming pools because it
Aprevents the growth of algae
Bcoagulates suspended particles
Cneutralizes dissolved gases in water
Dreacts with any excess chlorine present
Eincreases the amount of dissolved oxygen
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Question 684
waec 1995
Metals which react with steam only when they are red-hot include
Acopper
Bsodium
Ccalcium
Dgold
Eiron
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Question 685
waec 1995
The function of limestone in the extraction of iron in the blast furnace is
Aremoval of the earthly impurities
Bdecomposition of the iron ore
Cconversion of iron (lll) to iron (ll) compounds
Dgeneration of heat for the process
Econversion of coke to carbon(ll)oxide
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Question 686
waec 1995
Which of the following is an alloy of mercury?
AStainless steel
BSoft solder
CCoinage bronze
DAmalgam
EDuralumin
View Explanation & Discuss
Question 687
waec 1995

The following alkanols will yield alkanoic acids on reacting with excess acidified K2Cr2O7 except

ACH3CH2OH
B(CH3)2CHCH2OH
C(CH3)3CCH2OH
D(CH3)3COH
ECH3CH2CH2CH2OH
View Explanation & Discuss
Question 688
waec 1995
In which of the following processes are larger molecules broken down into smaller molecules?
AVulcanization of rubber
BHydrogenation of palm oil
CHydrolysis of starch
DPolymerization
EEsterification
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Question 689
waec 1995

The gas produced when a mixture of sodium propanoate and soda lime is heated is

Amethane
Bpentane
Cethane
Dbutene
Eethyne
View Explanation & Discuss
Question 690
waec 1995
Fructose and glucose are classified as carbohydrates because they
Aare crystalline white solids
Bare energy -giving substances
Care naturally occurring organic compounds
Dcontain carbon oxygen and hydrogen
Econform to the general formula Cx(H2O)y
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