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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.

49 questions JAMB 2505 WAEC 1623 NECO 168 CUSTOM 10

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49 questions

Question 1 of 20 49 total questions

Question 11

jamb 2010

2H2(g) + O2(g) ⇌ 2H2O(g) ΔH = -ve
what happens to the equilibrium constant of the reaction above if the temperature is increased?

Ait is unaffected

Bit becomes zero

Cit decrease

Dit increase

View Explanation & Discuss

Question 12

jamb 2010

The graph above demonstrate the effect of?

Asurface area on the rate of reaction

Bcatalyst on the rate of reaction

Cpressure on the rate reaction

Dconcentration on the rate of reaction

View Explanation & Discuss

Question 13

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

View Explanation & Discuss

Question 14

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

View Explanation & Discuss

Question 15

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

View Explanation & Discuss

Question 16

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

View Explanation & Discuss

Question 17

jamb 2010

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

Agold

Bsilver

Ccopper

Dzinc

View Explanation & Discuss

Question 18

jamb 2010

The IUPAC nomenclature of the compound LiAlH4 is?

Alithiumtetrahydridoaluminate (III)

Baluminium tetrahydrido lithium

Ctetrahydrido lithium aluminate (III)

Dlithium aluminium hydride

View Explanation & Discuss

Question 19

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 20

jamb 2010

Which of the following salts is slightly soluble in water?

AAgCl

BCaSO₄

CNa₂CO₃

DPbCl₂

View Explanation & Discuss

Question 21

jamb 2010

The colour of methyl orange in alkaline medium is?

Ayellow

Bpink

Corange

Dred

View Explanation & Discuss

Question 22

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

View Explanation & Discuss

Question 23

jamb 2010

The acid that is used to remove rust is?

Aboric

Bhydrochloric

Ctrioxonitrate (V)

Dtetraoxosulphate (VI)

View Explanation & Discuss

Question 24

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

View Explanation & Discuss

Question 25

jamb 2010

Coffee stains can best be removed by?

AKerosine

Bturpentine

Ca solution of borax in water

Dammonia solution

View Explanation & Discuss

Question 26

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 27

jamb 2010

Substance employed as drying agents are usually?

Aamphoteric

Bhygroscopic

Cefflorescent

Dacidic

View Explanation & Discuss

Question 28

jamb 2010

Permanent hardness of water can be removed by?

Afiltration

Badding slaked lime

Cadding caustic soda

Dboiling

View Explanation & Discuss

Question 29

jamb 2010

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

Akrypton

Bargon

Chelium

Dneon

View Explanation & Discuss

Question 30

jamb 2010

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

Aalpha decay

Bartificial transmutation

Cnuclear fussion

Dnuclear fission

View Explanation & Discuss

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