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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 1631

waec 1994

Sodium chloride is used in the following processes except in the

Atreatment of polluted water

Bpreservation of food

Cseparation of soap from glycerol

Dmanufacture of chlorine

Emanufacture of caustic soda

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Question 1632

waec 1994

Alkanols have unexpectedly high boiling points relative to their molar masses because of intermolecular

Ahydrogen bonding

Bmetallic bonding

Ccovalent bonding

Dionic bonding

Evan der Waals' forces

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Question 1633

waec 1994

What is the molar of hydrogen sulphide gas in the reaction H₂SO_4(aq) + 3H₂S_(g) → 4S_(s) + 4H₂O _(l)n represented by the following equation?

AReducing agent

BA bleaching agent

CA dehydrating agent

DA sulphonating agent

EAn oxidizing agent

View Explanation & Discuss

Question 1634

waec 1994

Which of the following reactions is accompanied by the first ionization energy of an element X?

AX ⁺_(aq) → X ²⁺ _(aq) + e-

BX ^- _(g) → X_(g) + ^e-

CX⁺ _(g) → X²⁺ +^e-

DX _(g) → X⁺ _(g) +^e-

EX_(s) → X ⁺ _(g) + ^e-

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Question 1635

waec 1994

The following compounds will decompose on heating except

ANaHCO₃

BK₂CO₃

CMgCO₃

DCa(HCO₃)₂

EZnCO₃

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Question 1636

waec 1994

In a chemical reaction, the reacting species possess energy of motion known as

Apotential energy

Bfree energy

Cbond energy

Dkinetic energy

Ehydration energy

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Question 1637

waec 1994

Which of the following electronic structures belongs to a noble gas?

A1s²2s²

B1s ²2s²2p⁴

C1s²2s²2p⁶3s²3p⁶

D1s²2s²2p²

E1s²2s²2p ⁶3s²3p³

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Question 1638

waec 1994

The positive of an element in the Periodic Table is determined by

Aits density

Bits atomic radius

Cits relative atomic mass

Dthe number of protons in its atom

Ethe number of neutrons in its atom

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Question 1639

waec 1994

Mg\(_2\) + 2HCI\(_{(aq)}\) → MgCI\(_{2(g)}\) + H\(_{2(g)}\).

From the equation above what mass of hydrogen would be produced if 12.0 g of magnesium reacted completely with dilute hydrochloric acid? (H = 1, Mg = 24)

A1.0g

B2.0g

C6.0g

D12.0g

E24.0g

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Question 1640

waec 1994

When water is dropped on calcium carbide, the gaseous product is an

Aalkane

Balkene

Calkyne

Dalkanol

Ealkanal

View Explanation & Discuss

Question 1641

waec 1994

How many faradays of electricity are required to liberate 9g aluminium? (AI = 27)

A0.1

B0.3

C1.0

D2.7

E3.0

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Question 1642

waec 1994

Glucose can be obtained from starch by

Ahydrogenation

Bdissoiation

Chydrolysis

Ddialysis

Edehydration

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Question 1643

waec 1994

If the volume of a given mass of gas at 0^oC is 27.3cm³, what will be the volume of the gas at 10^oC, pressure remaining constant?

A2.73cm³

B28.3cm³

C37.3cm³

D273cm³

E283cm³

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Question 1644

waec 1994

Which of the following occurs when an aqueous solution of sodium hydroxide is electrolysed using graphite electrodes?

ASodium metal is produced at the anode

BSodium amalgam is formed at the cathode

COxygen gas is produced at the anode

DThe grahite anode dissolves

EThe resulting solution becomes acidic

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Question 1645

waec 1994

When naphthalene on heating changes from the solid state directly to the gaseous state it undergoes

Aevaporation

Bsublimation

Cdecomposition

Dcombustion

Eionisation

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Question 1646

waec 1994

Calcium is usually extracted by the electrolysis of its

Atrioxonitrate (V)

Btetraoxosulphate (IV)

Coxide

Dhydride

Echloride

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Question 1647

waec 1994

Polyatomicity is illustrated by molecules of

Asulphur

Bcarbon (IV) oxide

Cnoble gases

Dliquefied oxygen

Eliquefied nitrogen

View Explanation & Discuss

Question 1648

waec 1994

The following will decolourize acidified potassium tetraoxomanganate (VII) solution except

Asulphur (lV) oxide

Bbut-3-ene

Cpentane

Dhydrogen sulphide

Epropyne

View Explanation & Discuss

Question 1649

waec 1994

Tetraoxosulphate (lV) acid is described as strong acid because it is highly

Acorrosive

Bconcentrated

Creactive

Dsoluble in water

Eionized in water

View Explanation & Discuss

Question 1650

waec 1994

The number of atoms in 1.2g of carbon - 12 isotope is

A1.00 x 10 ₂₂

B6.02 x 10₂₂

C1.20 x 10 ₂₃

D1.00 x 10₂₃

E6.02 x 10₂₄

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