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Chemistry Past Questions

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4,306 questions JAMB 2505 WAEC 1623 NECO 168 CUSTOM 10

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4,306 questions

Question 1 of 20 4,306 total questions

Question 621

waec 2015

A substance responsible for the sour taste of unripe orange is

AAlkene

BAlkanol

CAlkanoic acid

DAlkanoate

View Explanation & Discuss

Question 622

waec 2015

Which of the following process does not take place in domestic water treatment?

AChlorination

BFlocculation

CNeutralization

DSedimentation

View Explanation & Discuss

Question 623

waec 2015

Which of the following substances is a heavy chemical?

AAmmonia

BBarim Hydroxide

CHydrochloric acid

DTetraoxosulphate(VI)acid

View Explanation & Discuss

Question 624

waec 2015

Which of the following compounds is a secondary alkanol?

AEthanol

B2-methylbutan-2-ol

C3-methylpentan-2-ol

DPropan-1-ol

View Explanation & Discuss

Question 625

waec 2015

Starch could be converted to glucose by the process of

ACondensation

BDehydration

CFermentation

DHydrolysis

View Explanation & Discuss

Question 626

waec 2015

Which of the following reactions would take place when concentrated sodium hydroxide solution is added to palm oil?

AEsterification

BNeutralization

CPolymerization

DSaponification

View Explanation & Discuss

Question 627

waec 2015

A compound has an empirical formular CH₂O and molecular mass of 90.

[H = 1.00, C = 12.0, O = 16.0]

AC4H10O2

BC3H10O2

CC3H6O3

DC2H2O4

View Explanation & Discuss

Question 628

waec 2015

The complete hydrogenation of benzene gives

ACyclohexene

BCyclohexane

CHexene

DHexane

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Question 629

waec 2015

Which of the following metals is the strongest reducing agent?

ASodium

BSilver

CPotassium

DCopper

View Explanation & Discuss

Question 630

waec 2015

Consider the following reaction equation:
CuO_(s) + H_2(g) \(\to\) Cu_(s) + H₂O₍₁₎

Which substance is oxidized?

ACu

BCuO

CH₂

DH₂O

View Explanation & Discuss

Question 631

waec 2015

Which of the following statements about an electrochemical cell is correct? Oxidation occurs

AAt the anode

BAt the cathode

CThrough the salt bridge

DIn the aqueous solution

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Question 632

waec 2015

A change in the temperature of a saturated solution disturbs the equilibrium between the

AUndissolved solute and the solvent

BDissolved solute and the solvent

CDissolved solute and the undissolved solute

DDissolved solute and the solution

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Question 633

waec 2015

A substance which dissolves readily in organic solvent would

ABe a covalent compound

BHave strong electrostatic forces of attraction

Chave a high melting point

DConduct electricity in molten state

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Question 634

waec 2015

Which of the following compounds is the least soluble in water?

ACaCl₂

BCaSO₄

CNaCl

DNa₂SO₄

View Explanation & Discuss

Question 635

waec 2015

Solubility is practically applied in

AFractional distillation

BThe determination of pH

CThe determination of saturation in hydrocarbons

DSolvent extraction

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Question 636

waec 2015

Which of the following oxides can be reduced by hydrogen?

AAluminium oxide

BMagnesium oxide

CSodium oxide

DSilver oxide

View Explanation & Discuss

Question 637

waec 2015

An example of an acid salt is

ACH₃COOONa

BMg(OH)Cl

CNaHSO₄

D(NH₄)₂SO₄

View Explanation & Discuss

Question 638

waec 2015

The following diagram illustrates the rate curve that was obtained when Mg reacted with excess dilute HCl.

The diagram became horizontal at X because

AThe reaction was slowed down

BAll the dilute HCl has reacted

CAll the Mg has reacted

DHydrogen gas is produced at a steady rate

View Explanation & Discuss

Question 639

waec 2015

Which of the following statements about intermolecular distances and cohesive forces between gas is correct? They are

ABoth large

BBoth negligible

CConstant and negligible

DLarge and negligible

View Explanation & Discuss

Question 640

waec 2015

When a reaction is endothermic,

AEnthalpy change, \(\Delta\)H is negative

BHeat content of a product is less than the heat content of a reactant

CHeat content of reactants is less than the heat content of product

DThe reaction is non-spontaneous

View Explanation & Discuss

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