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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 1761

waec 1991

Which of the following is not a direct petroleum product?

AMethane

BEthanol

CPetrol

DVaseline

EKerosene

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Question 1762

waec 1991

Which of the reactions represented by the following equations will take place at room temperature?

AC 6 H₂O → CO + H₂

BCuO + H₂ → Cu + H₂O

CN₂ + 3H₂ → 2NH₃

D2Na + 2H₂O → 2NaOH + H₂

E2Fe + 3CI₂ → 2FeCI₃

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Question 1763

waec 1991

When starch undergoes complete enzyme-catalyzed hydrolysis, the resulting product is

Aglucose

Bmaltose

Csucrose

Dfructose

Ecellulose

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Question 1764

waec 1991

In the redox reaction represented by the following equation: Cu^{2+_aq + Zn_(s) → Cu_(s) + Zn²⁺}

Athe oxidation number of copper increases

Bcopper (ll) ions are reduced to copper atoms

Czinc atoms are reduced to zinc ions

Dcopper (ll) ions donate electrons to zinc atoms

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Question 1765

waec 1991

The ratio of reactants to products is 1: 3: 2 in the reaction represented by the equation below: N_{2,/SUB> _(g) → 2NH₃_(g) which of the following law is demonstrated by this?}

ABoyle's law

BLaw of multiple proportion

CGay Lussac's law

DLaw of constant composition

EAvogadro's law

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Question 1766

waec 1991

Esterification of propane 1,2,3-triol and unsaturated higher carboxylic acids will produce

Afats

Bsoap

Cmethly-propanoate

Dalkanols

Eoils

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Question 1767

waec 1991

2NaNO3 → 2NaNO2 + O2. From the equation above, what is the volume of oxygen produced at s.t.p. when 8.5g of 2NaNO3 is heated until no further gas is evolved? (2NaNO3 = 85, molar volume of gases at s.t.p. = 22.4dm3)

A1.12dm³

B2.24dm³

C4.48dm³

D11.2dm³

E22.4dm³

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Question 1768

waec 1991

Consider the reaction represented by the equation below: H2(g) + 12(s) ⇌ 2HI(g) ∆H negative. Which of the following takes place when the temperature of the reaction vessel is decreased?

Athe gases condense

Bthe yield of hydrogen increases

Cthe concentration of the reactants remain constant

Dmore of the hydrogen iodide decomposes

Ethe yield of hydrogen iodide increases

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Question 1769

waec 1991

CH₄_(g) + 2O₂_{(g) → 2H₂O_(l) + CO₂_(g) ∆H = 890KJ mo-₁ ∆H in the reaction represented by the equation above is the enthalpy of}

Aformation

Bcombustion

Csolution

Dactivation

Eneutralization

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Question 1770

waec 1991

A compound which liberates carbon (IV) oxide from a hydrogentrioxocarbonate (lV) could have the molecular formula

AC₂H₅OH

BC ₃H ₄

CHCOOH

DH₂O₂

EC₆H₆

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Question 1771

waec 1991

In which of the following are the substances arranged in their correct order of increasing melting point?

ASodium chloride, sulphur, diamond

BDiamond, sodium chloride, sulphur

CSulphur, sodium chloride, diamond

DDiamond, sulphur, sodium chloride

ESulphur, diamond, sodium chloride

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Question 1772

waec 1991

Which of the following statements is not correct? Group 7 elements

Aare diatomic

Bare good oxidizing agents

Care highly electronegative

Dhave relatively low ionization potentials

Ehave high electron affinity

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Question 1773

waec 1991

Which of the following modes of motion is exhibited by the particles of a solid?

AVibrational and random motion

BVibrational and translational motion

CTranslational and random motion

DVibrational motion only

ETranslational motion only

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Question 1774

waec 1991

The products of the electrolysis of dilute sodium chlorid solution with platinum electrodes are

Ahydrogen and oxygen

Boxygen and chlorine

Cchlorine and water

Dsodium amalgam and chlorine

Esodium hydroxide and water

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Question 1775

waec 1991

Which of the following formula is that of a dicarboxylic acid?

A(CH₃CH ₂)₂CHCOOH

BCH₂(OH)₂

CCH₃CH(OH)COOH

DCH₂(COOH)₂

ECH₃COCOOH

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Question 1776

waec 1991

Brass is an alloy of copper and

Airon

Bchromium

Czinc

Dtin

Emagnesium

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Question 1777

waec 1991

CH₂ = CH₂ + H₂SO₄ → CH₃ - CH₂ -OSO₃H. The reaction illustrated by the equation above is an example of

Asubstitution

Boxidation

Creduction

Daddition

Edisplacement

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Question 1778

waec 1991

Which of the following elements can from more than one acidic oxide?

AHydrogen

BSulphur

CCarbon

DAlumium

EIron

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Question 1779

waec 1991

Which of the processes represented by the following equations has the greatest positive entropy change?

AC₆H₃_(l) → C₆H ₆ _(g)

BH₂O _(s) → H₂O_(l)

CCuO_(s) + H₂_(g) → Cu_(s) + H₂

DNa₂CO₃_(s) + nH₂O_(l) →Na ₂CO₃nH₂O_(s)

ES_(s) → S_(l)

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Question 1780

waec 1991

What is the amount (in mole) of sodium trioxocarbonate (IV) in 5.3 g of the compound? (Na₂CO₃ = 106)

A0.05

B0.10

C0.20

D0.50

E2.00

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