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Chemistry Past Questions

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47 questions JAMB 2505 WAEC 1623 NECO 168 CUSTOM 10

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Past Questions

47 questions

Question 1 of 20 47 total questions

Question 1

jamb 1980

An endothermic reaction is one during which heat is.....and can be represented by the symbol.... which of the following combinations can be used accurately to complete the above definition?

Aliberated, -\(\Delta\)H

Bliberated, +\(\Delta\)H

Cabsorbed, -\(\Delta\)H

Dabsorbed, +\(\Delta\)H

Eabsorbed, +\(\Delta\)G

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Question 2

jamb 1980

Which of the following classes of organic compounds undergoes rapid oxidation with bromine water?

Aalcohols

Balkenes

Ccarboxylic acids

Desters

Ealkanes

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Question 3

jamb 1980

Detergents are more advantageous than soaps in hard water districts because

Aon treatment with hard water they either form soluble calcium salts or do not react with calcium ion

Bon treatment with hard water they form soluble calcium salts

Con treatment with hard water they form sodium salts

Don treatment with hard water they are converted into soaps

Eon treatment with hard water they form more lather than soaps does

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Question 4

jamb 1980

Which of the following derivatives of nitrogen affords an aqueous solution having a pH of less that 7?

AN₂O

BNO

CNO₂

DNaNO₃

ENH₃

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Question 5

jamb 1980

When copper (ii) sulphate solution is treated with excess ammonium hydroxide, a precipitate is first formed, and then this dissolves to give a deep blue solution.

This deep blue solution is a?

ACu(OH)₂

BCuSo₄.5H₂O

C(NH₄)₂SO₄

DCu(NH₃)₄(OH)₂

ECuSO₄.(NH₄)₂SO₄.2H₂O

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Question 6

jamb 1980

Which of the following tests would confirm-unequivocally that a solution X contain the sulphate ion if it gives with?

Asilver nitrates solution, a white precipates insoluble in dilute HNO₃

Bbarium chloride solution, a white precipitate insoluble in dilute H₂SO₄

Cbarium chloride solution, a white precipitate soluble in dilute HCl

Dbarium chloride solution a white precipitate soluble in dilute ammonia

Ebarium chloride solution a white precipitate insoluble in dilute HCl

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Question 7

jamb 1980

The following arrangement of elements in order of decreasing number of outer electrons; One of the elements is wrongly placed. Which is it? ALUMINIUM, CHLORINE, SILICON, MAGNESIUM AND SODIUM.

Achlorine

Baluminium

Csilicon

Dmagnesium

Esodium

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Question 8

jamb 1980

Copper sulphate solution was electrolysed using the apparatus show above. Which of the following changes are observed?

AThe bulb lights and copper is deposited at both electrodes

Bthe bulb lights and copper is deposited at the anode and disappears from the cathode

Cthe bulb lights and copper is deposited at the cathode and oxygen liberated at the anode

Dthe bulb lights and copper is deposited at the cathode and disappears from the anode

Ethe bulb lights but no additional changes are observed

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Question 9

jamb 1980

The following graph demonstrates the rate of reaction between calcium carbonate (marble)and dilute hydrochloric acid. The graph shows that the rate of reaction is initially greatest when

Athe initial slope of the curve is steepest and this occur when small pieces of marble are used and is due to a small surface area of reactant

Bthe occur when large pieces of marble are used and is due to a small surface area of reactant

Cthe initial slope of the curve is steepest and this occurs when small pieces of marble are used and is due to a large surface area of reactant

Dthe initial slope of the curve is steepest and this occur when large surface area of reactant

Ethe initial slope of the curve is least steep and this occur when small pieces of marble are used and is due to the increased surface area of the reactant

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Question 10

jamb 1980

Which of the following is the correct order in the above diagram increasing boiling point, of the isomeric \(C_{5}H_{12}\) compounds?

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Question 11

jamb 1980

Which of the following compounds will take up the molecules of bromine?

Bll

Clll

Dl and ll

El and lll

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Question 12

jamb 1980

The IUPAC name for the compound is

A2,3-dimethylpent-2,3-ene

B2, 3- dimethylpent-2-ene

C3, 4-dimethylpent-3-ene

D3,4-dimethylpentene

E3,4-dimethlhept-2-ene

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Question 13

jamb 1980

In the above experiment X is?

Apure nitrogen

Ba mixture of nitrogen and oxygen

Ca mixture of nitrogen and carbondioxide

Da mixture of oxygen and inert gases

Ea mixture of nitrogen and inert gases

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Question 14

jamb 1980

When chlorine gas is passed into a solution of sulphur dioxide?

Asulphur dioxide is reduced to sulphur

Bthe chlorine is oxidized to hydrochloric acid

Cdilute sulphuric acid and hydrochloric acid are produced

DHydrochloric acid and sulphur are produced

Esulphur trioxide is the only product

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Question 15

jamb 1980

A mixture of ethanol, sodium dichromate, and water is allowed to drop gradually into a boiling solution containing one part concentrated H₂SO
₄ and the liberate gas is collected by cooling it with ice water to give a liquid. This liquid is?

Aethanoic acid

Bacetaldehyde

Cethyl acetate

Dmethanol

Eethylene

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Question 16

jamb 1980

Which of the following statement is false?

AAcids react with some metals, liberating hydrogen

BAcids react with carbonates, liberating carbondioxide

CAcids conduct electricity and are decomposed by the current, liberating hydrogen at the anode

DAcids have a sour taste

EAcids change the colour of indicators

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Question 17

jamb 1980

If one of the following oxides is heated with hydrogen or carbon using a bunsen burner, it is not reduced to the metal. Which one is it?

ALead oxide

BMagnesium oxide

CCopper oxide

DTin oxide

EIron oxide

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Question 18

jamb 1980

Cellulose and starches can be classified as one of the following?

Asugars

Bsucrose

Chydrocarbons

Dcarbohydrates

Eisomers

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Question 19

jamb 1980

The best way of collecting chlorine is?

Aby downward displacement of air

Bby upward displacement of air

Cover water

Dunder water

Eover mercury

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Question 20

jamb 1980

A cold aqueous solution of sodium chloride is electrolyzed using a graphite anode and an iron cathode. In the course of the electrolysis the electrolyte is continuously stirred. The liquid left after electrolysis will therefore consist of?

Asodium hydroxide solution

Bchlorine water

Cpure water

Dsodium hypochlorite solution

Ehydrochloric acid solution

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