Chemistry Past Questions

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

1,623 questions
Question 1 of 20 1,623 total questions
Question 561
waec 2001

Sugars can be hydrolyzed at room temperature by the action of

Amineral acids
Bstrong bases
Cenzymes
Doxidants
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Question 562
waec 2001

Which of the following constitutes an advantage in the use of hard water?

AFormation of scum with soap
BFurring of kettles
CBlockage of water pipes
DFormation of strong bones
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Question 563
waec 2001

What is the function of H2SO4 in the following reaction?

C12H22O11 conc. H2SO4 → 12C + 11H2O

AOxidizing agent
BStrong acid
CDehydrating agent
DCatalyst
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Question 564
waec 2001

Which of the following polymers contains nitrogen?

ANylon
BPolyvinyl chloride
CPolyethene
DCellulose
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Question 565
waec 2001

One of the products of combustion of pentane in excess air is

Apentanol
Bpentene
Cnitrogen (ll) oxide
Dcarbon (IV) oxide
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Question 566
waec 2001

Benzene produces more soot than ethene on burning because benzene

Ahas a higher molar mass
Bhas a higher degree of unsaturation
Cundergoes substitution and addition reactions
Dis a liquid at room temperature
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Question 567
waec 2001

Hydrogenation of butene yields

Abutyne
Bbutane
Cpentence
Dbutanol
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Question 568
waec 2001

A feasible cell was constructed by joining the two half cells below. Cu\(^{2+}\) (aq) + 2e\(^-\) → Cu(s) E\(^0\) = +0.34 V; Zn\({^2+}\) + 2e\(^-\) → Zn\((_s)\) E\(^0\) = - 0.76V. What is the standard e.m.f. of the cell?

A- 1.1V
B- 0.42V
C+0.42V
D+1.1V
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Question 569
waec 2001

In the electrolysis of CuSO4(aq) using copper electrodes, the reaction at the anode is

Adischarge of SO4 2-
Bdischarge of OH-
Cdissolution of copper electrode
Devolution of oxygen
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Question 570
waec 2001

Given that the order of reactivity of four metals is P>Q>R>S, which of the following reactions is feasible?

AS + P+ → P + S +
BQ + S+ → S + Q+
CR + P+ → P + R+
DS + Q+ → Q + S+
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Question 571
waec 2001

A concentrated solution containing H+, Cu2+,OH- and CI- was electrolyzed using platinum electrodes which of the ions will be discharged at the cathode?

AH+
BCu2+
COH-
DCI-
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Question 572
waec 2001

Which of the following substances decomposes when an electric current is passed through it?

AGlucose solution
BZinc rod
CHydrochloric acid
DTetrachloromethane
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Question 573
waec 2001

What is oxidized in the reaction represented by the following equation? 3CU + 8HNO3 → 3Cu(NO3)2 + 2NO + 4H2O

AOxygen
BHydrogen
CNitrogen
DCopper
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Question 574
waec 2001

What is the oxidation number of nitrogen in Al(NO\(_3\))\(_3\)?

A+ 1
B+ 3
C+ 5
D+ 6
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Question 575
waec 2001

A reaction is represented by the equation below. A2(g) + B2(g)  → 2AB(g); ∆H = +X kJmol-1 Which of the following statements about the system is correct?

AThe reaction goes to completion at equilibrium
BThe forward reaction is exothermic
CAt equilibrium increase in temperature favours the reverse reaction
DPressure has no effect on the equilibrium mixture
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Question 576
waec 2001

Consider the following equation: Ag+ (aq) + CI-(aq) → Ag+CI- (s) ; ∆H = - 65.7 kJmol-1. From the equation, it can be deduced that

Adirect combination is involved and the reaction is endothermic
Ba solid is formed and heat is evolved
Cactivation energy is high and a catalyst is required
Dthe reaction is endothermic and occurs at high temperature
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Question 577
waec 2001

What does ∆H represent in the following equation ? Cl(g) + e- → CI- (g); ∆H = - 363 kJ mol-1

Alonization energy
BElectron affinity
CDissociation energy
DHeat of atomization
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Question 578
waec 2001

It can be concluded that gastric juice

Acontains enzymes
Bis acidic
Cis a mixture
Dhas pH value of 7
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Question 579
waec 2001

A gas was evolved when a sample of gastric juice reacted with sodium trioxocarbonate (IV) . The gas evolved was

ANH3
BSO2
CHCI
DCO2
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Question 580
waec 2001

In which of the reactions represented by the following equations is HNO3 behaving as a typical acid?

ACaO + 2HNO3 → Ca(NO3) 2 + H 2O
BCu + 4HNO3 → Cu(NO 3)2 + 2H2O + 2NO2
CS + 6HNO3 → H2SO 4 + 6NO2 + 2H2O
DP + 5HNO3 → H 3PO 4 + 5NO2 + H2O
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