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Chemistry Past Questions

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84 questions JAMB 2505 WAEC 1623 NECO 168 CUSTOM 10

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84 questions

Question 1 of 20 84 total questions

Question 21

jamb 1991

Which of the following are the products of the reaction between CH₃COOH and CI₂ in sunlight?

ACICH₂COOH + HCI

BCH₃COCI + HOCI

CCH₃COOCI + HCI

DCH₃COCI + HO₂

View Explanation & Discuss

Question 22

jamb 1991

Which of the following statements is TRUE of the complete hydrolysis of a glycerine by sodium hygroxide?

A3 moles ofNaOH are required for each mole of glyceride

B3 moles of glycerol are produced

COnly one mole of soap is formed

Dconcentrated H₂SO₄ is essential for the completion of the reaction

View Explanation & Discuss

Question 23

jamb 1991

Is known as?

A1-chloro-2-methylbutane

B1-chloro-2-methylpropane

C2-chloromethylpropane

D1-chloro-2, 2-dimethylethane

View Explanation & Discuss

Question 24

jamb 1991

A certain liquid has a high boiling point. It is viscous, non-toxic, miscible with water being very hygroscopic. This liquid is most likely to be?

ACH₃CH₂CH₂HO

BCH₃CHOHCH₃

CCH₃CH₂CHOHCH₃

DCH₂OHCHOHCH₂OH

View Explanation & Discuss

Question 25

jamb 1991

One advantages of detergents over soap is that detergents?

Aare easier to maufacture

Bfoam more than soap

Cform soluble salts with hard water

Dare able to deter germs more than soap

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Question 26

jamb 1991

Ethene when passed into concentrated H₂SO₄ is rapidly absorbed. The product is diluted with water and then warmed to produce?

Aethanol

Bdiethyl ether

Cethanal

Ddiethyl sulphate

View Explanation & Discuss

Question 27

jamb 1991

How many grams of bromine will be required to completely react with 10 g of propyne?

(C = 12, H = 1, Br = 80)

A20 g

B40 g

C60 g

D80 g

View Explanation & Discuss

Question 28

jamb 1991

Which of the following compounds can exist as geometric isomers?

A2-methylbut-2ene

BBut-2-ene

CBut-1-ene

DCI-C-Br

View Explanation & Discuss

Question 29

jamb 1991

Copper (II) tetraoxosulphate (IV) is widely used as a?

Afertilizer

Bfungicide

Cdisinfectant

Dpurifier

View Explanation & Discuss

Question 30

jamb 1991

Which of the following metals can be prepared in samples by the thermal decomposition of their trioxonitrate (V) salts?

ACopper and mercury

BSilver and copper

CMercury and silver

DMagnesium and mercury

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Question 31

jamb 1991

Which of the following, in clear solution, forms a white precipitate when carbon (IV) oxide is bubbled into it for a short time?

AKOH

BNaOH

CCa(OH)₂

DAI(OH)₃

View Explanation & Discuss

Question 32

jamb 1991

Addition of aqueous ammonia to a solution of Zn⁺⁺ gives a white precipitate which dissolves in an excess of ammonia because?

Azinc is amphoteric

Bzinc hydroxide is readily soluble

Czinc forms a complex which is readily soluble in excess ammonia

Dammonia solution is a strong base

View Explanation & Discuss

Question 33

jamb 1991

Oxygen gas can be prepared by heating?

Aammonium trioxonitrate (V)

Bammonium trioxonitrate (III)

Cpotassium trioxonitrate (V)

Dmanganese (IV) oxide

View Explanation & Discuss

Question 34

jamb 1991

Which of the following salts can be melted without decomposition?

ANa₂CO₃

BCaCO₃

CMgCO₃

DZnCO₃

View Explanation & Discuss

Question 35

jamb 1991

Which of the following gases will rekindle a brightly glowing splint?

ANO₂

BNO

CN₂O

DCI₂

View Explanation & Discuss

Question 36

jamb 1991

Which of the following equilibria is unaffected by a pressure change?

A2NaCI(s) ↔ 2Na _(I) + CI_2(g)

BH _2(g) + I_2(g) ↔ 2HI_(g)

C2O_3(g) ↔ 3O_2(g)

D2NO_2(g) ↔ N₂O_4(g)

View Explanation & Discuss

Question 37

jamb 1991

NO(g) + CO(g) ↔ (1)/(2)N2(g) + CO2(g) ∆H = 89.3 kj.
What conditions would favour maximum conversion of nitrogen (II) oxide and carbon (II) oxide in the reaction above?

ALow temperature and high pressure

BHigh temperature and low pressure

CHigh temperature and high pressure

DLow temperature and low pressure

View Explanation & Discuss

Question 38

jamb 1991

1.1 g of CaCI2 dissolved in 50 cm3 of water caused a rise in temperature of 3.4°C. The heat of reaction, ∆H for CaCI2 in kj per mole is?

(Ca = 40, CI = 35.5, specific heat of water is 4.18 jk-1)

A-71.1

B-4.18

C+71.1

D+111.0

View Explanation & Discuss

Question 39

jamb 1991

Magnesium (IV) oxide is known to hasten the decomposition of hydrogen peroxide. Its main action is to?

Aincrease the surface area of the reactants

Bincrease the concntration of the reactants

Clower the activation energy for the reaction

Dlower the heat of reaction, ∆H, for the reaction

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Question 40

jamb 1991

2H2S(g) + SO2(g) → 3S(s) + 2H2O(I). The above reaction is?

Aa redox reaction H₂S is the oxidant and SO₂ is the reductant

Ba redox reaction in which SO₂ is the oxidant and H₂S is the reductant

Cnot a redox reaction because there is no oxidant in reaction equation

Dnot a redox because there is no reductant in the reaction equation

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