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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.

2,505 questions JAMB 2505 WAEC 1623 NECO 168 CUSTOM 10

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2,505 questions

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Question 751

jamb 2000

The distance between the nuclei of chlorine atoms in a chlorine molecule is 0.194 mm. The atomic radius of chlorine atom is

A0.097 mm

B0.194 mm

C0.388 mm

D2.388 mm

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Question 752

jamb 2000

The shapes of CO\(_2\), H\(_2\)O and CH\(_4\) respectively are

Abent, linear and tetrahedral

Bbent, tetrahedral and linear

Clinear, bent and tetrahedral

Dtetrahedral, linear and bent

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Question 753

jamb 2000

The knowledge of half-life can be used to

Acreate an element

Bdetect an element

Csplit an element

Dirradiate an element

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Question 754

jamb 2000

Which of the following types of bonding does not involve the formation of new substance?

AMetallic

Bcovalent

CCo-ordinate

DElectrovalent

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Question 755

jamb 2000

The electron configuration of \(_{22}X^{2+}\) ion is

A1s² 2s²2p⁶ 3s² 3p⁶ 4s² 3d²

B1s² 2s²2p⁶ 3s² 3p⁶ 4s² 3d¹

C1s² 2s²2p⁶ 3s² 3p⁶

D1s² 2s²2p⁶ 3s² 3p⁶ 3d²

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Question 756

jamb 2000

Which of the following statement is correct about the periodic table?

AElements in the same period have the same number of valency electron

BThe valence electron of the elements in the same period increase progressively across the period

CElements in the same group have the same number of electron shells

DThe non-metallic properties of the elements tend to decrease across each period

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Question 757

jamb 2000

The fundamental difference between the three states of matter is the

Ashape of their particles

Bnumber of particles in each state

Cshape of the container they occupy

Ddegree of movement of their particles

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Question 758

jamb 2000

The partial pressure of oxygen in a sample of air is 452 mm Hg and the total pressure is 780 mm Hg. What is the mole fraction of oxygen?

A0.203

B0.579

C2.030

D5.790

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Question 759

jamb 2000

The ratio of the initial to final pressure of a given mass of gas is 1:1.5. Calculate the final volume of the gas if the initial volume was 300 cm³ at the same temperature

A120 cm³

B200 cm³

C450 cm³

D750 cm³

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Question 760

jamb 2000

How many moles of HCl will be required to react with potassium heptaoxodichromate (VI) to produce 3 moles of chlorine?

A14

B12

C11

D10

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Question 761

jamb 2000

50 cm³ of carbon (II) oxide was exploded with 150 cm³ of air containing 20% oxygen by volume. Which of the reactants was in excess?

ACarbon (II) oxide

BCarbon (IV) oxide

COxygen

DNitrogen

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Question 762

jamb 2000

Which of the following compounds is composed of Al, Si, O and H?

AEpsom salt

BLimestone

CClay

DUrea

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Question 763

jamb 2000

Sieving is a technique used to separate mixture containing solid particles of

Asmall sizes

Blarge sizes

Cdifferent sizes

Dthe same sizes

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Question 764

jamb 2000

A mixture of iodine and sulphur crystals can be separated by treatment with?

AWater to filter off sulphur

Bcarbon (IV) sulphide to filter off iodine

Cethanoic acid to filter off sulphur

Dmethanol to filter off iodine

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Question 765

jamb 1999

Which of the compounds above would react to take up two molecules of bromine durng bromination?

Al only

Blll only

Cl and ll only

Dll and lll only

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Question 766

jamb 1999

In the diagram above, the mixture of the solids P and Q can be separated by?

Adistillation

Bfractional distillation

Ccrystallization

Dfractional crystallization

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Question 767

jamb 1999

Use the table above to answer this question .The least reactive element is

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Question 768

jamb 1999

Use the table above to answer this question . The element that is likely to participate in covalent rather than ionic bonding is

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Question 769

jamb 1999

In the diagram above, Y is a mixture of

Acalcium hydroxide and ammonium chloride

Bcalcuim hydroxide and sodium chloride

Csodium chloride and ammonuim trioxonitrate (V)

Dsodium dioxonitrate (lll) and ammouium chloride

View Explanation & Discuss

Question 770

jamb 1999

From the diagram above the mass of crystals deposited when 1 dm ³ of a saturated solution of NaCl is cooled from 80 ^oC to 60^oC is
[Na = 23, Cl = 35.5]

A117.00 g

B58.50 g

C11.70 g

D5.85 g

View Explanation & Discuss

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