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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.

90 questions JAMB 2505 WAEC 1623 NECO 168 CUSTOM 10

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90 questions

Question 1 of 20 90 total questions

Question 11

waec 2014

The gases produced when Cu(NO₃)_2(s) was heated are

ANO and NO₂

BO₂ and NO

CNO₂ and N₂O₄

DO₂ and NO₂

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Question 12

waec 2014

Which of the following substances with the corresponding pH value is an alkali?
Substance pH

ALime 2.4

BBanana 4.6

CDistilled water 7.0

DMilk of magnesia 10.5

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Question 13

waec 2014

Zinc oxide is said to be amphoteric because it

Aforms an acid salt

Bis an insoluble base

Cforms a double salt

Dreacts with a base or an acid

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Question 14

waec 2014

The type of energy changes that accompany the mixing of a strong acid to a strong base is

Aelectrical

Bheat

Clight

Dsound

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Question 15

waec 2014

Which of the following statements about volatile liquids is correct? They have

Ahigh vapour pressure and low boiling point

Bhigh vapour pressure and high boling point

Clow vapour pressure and low boining point

Dlow vapour pressure and high boiling point

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Question 16

waec 2014

The vapour pressure of a given volume of liquid increase when the

Aliquid becomes saturated with a salt

BVolume of the liquid increases

Ctemperature of the liquid falls

Dtemperature of the Liquid rises

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Question 17

waec 2014

Which of the following relationships correctly expresses the Boyle's law?

AP \(\alpha\) V at constant T

BV \(\alpha\) T at constant P

CP \(\alpha\) \(\frac{1}{V}\) at constant T

DV \(\alpha\) \(\frac{1}{T}\) at constant P

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Question 18

waec 2014

Which of the following statements about a chemical system in equilibrium is correct/ The

Areaction is irreversible

Breaction goes to completion

Cequilibrium is re-established when a stress is applied

Dequilibrium position is affected by catalyst

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Question 19

waec 2014

The mass of 800cm3 of gas Q at s.t.p. is 1.0g. What is the molar mass of Q? [Avogadros c mol-1`]

A18.0 gmol^-1

B22,4gmol^-1

C28.0gmol^-1

D36.0 gmol^-1

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Question 20

waec 2014

If 0.20 mol dm^-3 NaOH_(aq) was evaporated to yield 5.0g of solid NaOH, calculate the volume of NaOH _(aq) used. (Na = 23.0,O = 16:0; H = 1.00)

A600cm-³

B625cm³

C1000³

D1600 cm ³

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Question 21

waec 2014

The oxidation number of sulphur in Fe₂(SO₄)₃ is

A+2.

B+3

C+4.

D+6.

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Question 22

waec 2014

A gaseous mixture contains 0,256 g of hydrogen and 2.00 g of oxygen. The mole ration of hydrogen to oxygen in the mixture is (H=1.00; O=16,0)

A1:1

B2:1

C1:4

D8:1

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Question 23

waec 2014

An aqueous solution of Na₂CO₃ is

Aacidic

Balkaline

Camphoteric

Dneutral

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Question 24

waec 2014

How many lone pair (s) of electrons is present in HF?

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Question 25

waec 2014

NH₄^- is formed from NH₃ and H^- by

Acovalent bonding

Bdative bonding

Chydrogen bonding

Dionic bonding

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Question 26

waec 2014

The relative atomic mass of chlorine is not a whole number because

Ait is the weighted average mass of all its various isotopes

Bit is the average mass of all the isotopes of the element

Cthe element has strong oxidizing ability

Dthe atom contains a higher number of neutrons than protons

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Question 27

waec 2014

An atom W has 17 electrons and 18 neutrons. Which of the following representations of the atom is correct?

A¹⁷₁₈W

B¹⁸₁₇W

C³⁵₁₇W

D³⁵₁₈W

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Question 28

waec 2014

Which of the following transition metals is not attracted to external magnetic field?

ACu

BFe

CTi

DZn

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Question 29

waec 2014

The electron configuration of \(_{26}Fe^{3+}\) is?

A[Ar]4s²3d⁶

B[AR]4s²3d³

C[AR]4s¹3d⁴

D[AR]4s⁰3d⁵

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Question 30

waec 2014

Which of the following processes is used in food preservation in an industry?

ACarbon dating

BIeeadiation of gamma rays

CNuclear fission

DNuclear fusion

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