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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

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Question 691

waec 1994

When magnesium ribbon burns in air, the products are

Amagnesium nitride and magnesium oxide

Bmagnesium nitride and carbon (ll) oxide

Cmagnesium oxide and steam

Dmagnesium nitride and soot

Emagnesium oxide and carbon (ll) oxide

View Explanation & Discuss

Question 692

waec 1994

Destructive distillation of coal means

Aheating coal in plentiful supply of air

Bburning coal in air to produce water and carbon (IV) oxide

Cheating coal in the absence of air

Dheating coal in limited supply of air

Eseparating coal into various allotropes of carbon

View Explanation & Discuss

Question 693

waec 1994

Study the reaction represented by the equation: Alkanol + Alkanoic acid + conc. H\(_2\)SO\(_4\) → Alkanoate + water. The type of process involved in the reverse reaction is

ANeutralization

Bdehydration

Chydrolysis

Ddecomposition

Ehydrogenation

View Explanation & Discuss

Question 694

waec 1994

Which of the following is likely to have the highest degree of hardness?

ACarbonated water

BDistilled water

CAcidified water

DRain water

ELime water

View Explanation & Discuss

Question 695

waec 1994

Which of the following is not a halogen?

ASilicon

BFluorine

CAstatine

DBromine

Elodine

View Explanation & Discuss

Question 696

waec 1994

The gaseous product formed when ammonia is passed over heated copper (ll) oxide is

Aoxygen

Bnitrogen

Chydrogen

Dnitrogen (l) oxide

Enitrogen (ll) oxide

View Explanation & Discuss

Question 697

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

View Explanation & Discuss

Question 698

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

View Explanation & Discuss

Question 699

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 700

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-

View Explanation & Discuss

Question 701

waec 1994

The following compounds will decompose on heating except

ANaHCO₃

BK₂CO₃

CMgCO₃

DCa(HCO₃)₂

EZnCO₃

View Explanation & Discuss

Question 702

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

View Explanation & Discuss

Question 703

waec 1994

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

A1s²2s²

B1s ²2s²2p⁴

C1s²2s²2p⁶3s²3p⁶

D1s²2s²2p²

E1s²2s²2p ⁶3s²3p³

View Explanation & Discuss

Question 704

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 705

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

View Explanation & Discuss

Question 706

waec 1994

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

Aalkane

Balkene

Calkyne

Dalkanol

Ealkanal

View Explanation & Discuss

Question 707

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

View Explanation & Discuss

Question 708

waec 1994

Glucose can be obtained from starch by

Ahydrogenation

Bdissoiation

Chydrolysis

Ddialysis

Edehydration

View Explanation & Discuss

Question 709

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

View Explanation & Discuss

Question 710

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

View Explanation & Discuss

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