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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.

1,623 questions JAMB 2505 WAEC 1623 NECO 168 CUSTOM 10

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1,623 questions

Question 1 of 20 1,623 total questions

Question 521

waec 2003

Which of the following salts can be prepared by reacting the metal with dilute H₂SO₄?

ACuSO₄

BMgSO₄

CBaSO₄

DPbSO₄

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Question 522

waec 2003

Bees inject an acidic substance when they sting. Which of the following chemical could be used to treat bee stings?

ACH₃COOH

BNaHCO₃

CC₂H₅OH

DH₂O₂

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Question 523

waec 2003

Which of the following acids is dibasic?

AHydrochloric acid

BTrioxosulphate (IV) acid

CDioxonitrate (lll) acid

DEthanoic acid

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Question 524

waec 2003

Which of the following quantities is the same for one mole of Br_2(l) and one mole of He_(g)?

ANumber of molecules

BNumber of atoms

CTotal mass of the particles

DVolume occupied at s.t.p

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Question 525

waec 2003

Which of the following statements about dative bonding is not correct?

Athere is sharing of electrons

Bone atom must possess a lone pair electrons

Ceach participating atom contributes one electron

Dit can be formed between molecules

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Question 526

waec 2003

An element X with electronic configuration \(1S^22S^22P^63S^2\) combines with another element Y with the configuration \(1S^2S^22P^23S^23P^5\). What is the formula of the compound formed?

AX₂Y₅

BX₂Y₃

CXY₃

DXY₂

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Question 527

waec 2003

Group O of elements are unreactive because

Atheir outmost shells contain equal number of electrons

Btheir highest occupied enegy level is full

Cthey are monatomic gases

Dthey are non-metals

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Question 528

waec 2003

The electronic configuration of an element is 1\(s^2\) 2\(s^2\) 2\(p^6\) 3\(s^2\) 3\(p^3\). Where is the element located in the periodic table?

AGroup lll, period 3

BGroup lll, period 5

CGroup V, period 3

DGroup V, period 5

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Question 529

waec 2002

One of the methods used for combating air pollution is

Aburning of solid waste

Bprovision of sanitary land fills

Clegislation against some industrial practices

Dscavenging of refuse dumps

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Question 530

waec 2002

Iron is often galvanized in order to

Amake it more malleable

Bremove the impurities in it

Cprotect it against corrosion

Drender it passive

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Question 531

waec 2002

The energy value of petrol can be determined by a

Abomb calorimeter

Bcatalytic cracker

Cfractionating column

Dthermometer

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Question 532

waec 2002

The reaction of sucrose with dilute HCI produces

Aan alkanoate

Bglucose and fructose

Ca black mass of carbon

Da polysaccharide

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Question 533

waec 2002

A suitable reagent for distinguishing between ethanoic acid ethanol is

Abromine water

BFehling's solution

Csodium hydrogentrioxocarbonate (IV)

Dammoniacal silver trioxonitrate (V)

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Question 534

waec 2002

Which of the following types of alkanols undergo oxidation to produce alkanoic acids? I. Primary alkanols II. Secondary alkanols III. Tertiary alkanols

AI,II and III

Bl and ll only

Cll only

Dl only

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Question 535

waec 2002

Which of the following statements about soapless detergents is correct? They

Alather readily with hard water

Bincrease the surface tension of water

Ccause hydrolysis of salts in water

Dfrom a curdy precipitate with soft water

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Question 536

waec 2002

The reaction between ethene and chlorine to form 1, 2-dichloroethane is

Aoxidation

Bpolymerization

Caddition

Dsubstitution

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Question 537

waec 2002

The following compounds are hydrocarbons except

Amethylpropanoate

B2-methylbutane

Cbenzene

Dcyclohexane

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Question 538

waec 2002

When alkynes are hydrogenated completely they produce compounds with the general molecular formula

AC_nH_n

BC_nH_2n

CC_nH_2n+2

DC_nH_2n-2

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Question 539

waec 2002

Which of the following compounds can be represented by the molecular formula C₂H₆O?

APropanal

BEthanol

CMethanoic acid

DGlucose

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Question 540

waec 2002

Which of the following processes takes place during the production of margarine from vegetable oils?

AEsterification

BHydrolysis

CHydrogenation

DSaponification

View Explanation & Discuss

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