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Chemistry Past Questions

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87 questions JAMB 2505 WAEC 1623 NECO 168 CUSTOM 10

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87 questions

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Question 31

jamb 2010

In the preparation of oxygen by heating KClO\(_3\) in the presence of MnO\(_2\), only moderate heat is needed because the catalyst acts by?

Alowering the pressure of the reaction

Bincreasing the surface area of the reactant

Cincrease the rate of the reaction

Dlowering the energy barrier of the reaction

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Question 32

jamb 2010

If a reaction is exothermic and there is a great disorder, it means that?

Athe reaction is static

Bthe reaction is in a state of equilibrium

Cthere will be a large increase in free energy

Dthere will be a large decrease in free energy

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Question 33

jamb 2010

In which of the following is the entropy change positive?

AThermal dissociation of ammonium chloride

BReaction between an acid and a base

CAddition of concentrated acid to water

DDissolution of sodium metal in water

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Question 34

jamb 2010

What quantity of aluminum is deposited when a current of 10A is passed through a solution of an aluminum salt for 1930s?
[Al = 27, F = 96500 C mol -1]

A0.2 g

B1.8 g

C5.4 g

D14.2 g

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Question 35

jamb 2010

Iron can be protected from corrosion by coating the surface with?

Agold

Bsilver

Ccopper

Dzinc

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Question 36

jamb 2010

The IUPAC nomenclature of the compound LiAlH4 is?

Alithiumtetrahydridoaluminate (III)

Baluminium tetrahydrido lithium

Ctetrahydrido lithium aluminate (III)

Dlithium aluminium hydride

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Question 37

jamb 2010

6\(AgNO_{4(aq)} + PH_{3(g)} + 3H_2O_{(l)}\) → 6\(Ag_{(s)} + H_3PO_{3(g)} + 6HNO_{3(aq)}\)
In the above reaction, the reducing agent is?

AHNO_3(aq)

BH₂O_(l)

CPH_3(g)

DAgNO_3(aq)

View Explanation & Discuss

Question 38

jamb 2010

Which of the following salts is slightly soluble in water?

AAgCl

BCaSO₄

CNa₂CO₃

DPbCl₂

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Question 39

jamb 2010

The colour of methyl orange in alkaline medium is?

Ayellow

Bpink

Corange

Dred

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Question 40

jamb 2010

Calculate the volume of 0.5 mol dm\(^{-3}\) H\(_2\)SO\(_4\) that is neutralized by 25 cm\(^3\) of 0.1 mol dm\(^3\) NaOH?

A5.0 cm³

B2.5 cm³

C0.4 cm³

D0.1 cm³

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Question 41

jamb 2010

The acid that is used to remove rust is?

Aboric

Bhydrochloric

Ctrioxonitrate (V)

Dtetraoxosulphate (VI)

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Question 42

jamb 2010

Carbon (II) oxide is considered dangerous if inhaled mainly because it?

Acan cause injury to the nervous system

Bcompetes with oxygen in the blood

Ccompetes with carbon (IV) oxide in the blood

Dcan cause lung cancer

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Question 43

jamb 2010

Coffee stains can best be removed by?

AKerosine

Bturpentine

Ca solution of borax in water

Dammonia solution

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Question 44

jamb 2010

Calculate the solubility in mol dm-3 of 40g of CuSO4 dissolved in 100g of water at 120°C?
[Cu = 64, S = 32, O = 16]

A4.00

B2.50

C0.40

D0.25

View Explanation & Discuss

Question 45

jamb 2010

Substance employed as drying agents are usually?

Aamphoteric

Bhygroscopic

Cefflorescent

Dacidic

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Question 46

jamb 2010

Permanent hardness of water can be removed by?

Afiltration

Badding slaked lime

Cadding caustic soda

Dboiling

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Question 47

jamb 2010

A noble gas with a high power of fog penetration used in aerodrome beacons is?

Akrypton

Bargon

Chelium

Dneon

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Question 48

jamb 2010

12D + 13T → 24He + 01n + energy
The reaction above illustrates?

Aalpha decay

Bartificial transmutation

Cnuclear fussion

Dnuclear fission

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Question 49

jamb 2010

Elements in the same period in the periodic table have the same?

Anumber of shells

Batomic number

Cchemical properties

Dphysical properties

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Question 50

jamb 2010

The maximum number of electrons in the L shell of an atom is?

C18

D32

View Explanation & Discuss

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