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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.

45 questions JAMB 2505 WAEC 1623 NECO 168 CUSTOM 10

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45 questions

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Question 11

jamb 2014

In an equilibrium reaction, which of the following conditions indicates that maximum yield of the product will be obtained?

AEquilibrium constant is very large

B∆H - T∆S = O

C∆ H > T ∆ S

DEquilibrium constant is less than zero

View Explanation & Discuss

Question 12

jamb 2014

If the change in free energy of a system is -899 Jmol^-1 and the entropy change is 10Jmol^-1k^-1 at 250C, calculate the enthalpy change.

A+2081 Jmol^-1

B-2081 Jmol^-1

C-649 Jmol^-1

D+649 Jmol^-1

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Question 13

jamb 2014

How many faraday of electricity is required to produce 0.25 mole of copper?

A1.00F

B0.01F

C0.05F

D0.50F

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Question 14

jamb 2014

Calculate the quantity of electricity in coulombs required to liberate 10g of copper from a copper compound

[Cu=64, F = 96500 Cmol-1]

A32395.5

B30156.3

C60784.5

D15196.5

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Question 15

jamb 2014

\(H_2O_{(g)} + C_{(s)} → H_{2(g)} + CO_{(g)}\)

The oxidizing agent in the reaction above is

ACO_(g)

BC_(s)

CH₂O_(g)

DH₍₂₎_(g)

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Question 16

jamb 2014

Zn _(s) + CuSO ₄(aq) → ZnSO ₄(aq) + Cu _(s)
In the reaction above, the oxidation number of the reducing agent changes from

A0 to + 4

B0 to + 2

C+ 1 to + 2

D+ 1 to + 3

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Question 17

jamb 2014

Which of the following salts will turn blue litmus red?

ASodium tetrahydroxozincate (ll)

BSodium hydrogentetraoxosulphate (VI)

CSodium trioxocarbonate (lV)

DZinc chloride hydroxide

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Question 18

jamb 2014

The mathematical expression of PH is

Alog ₁₀[OH^-]

Blog ₁₀1/[H ₃ O⁺]

Clog ₁₀[H ₃ O⁺]

Dlog ₁₀1/[OH ^-]

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Question 19

jamb 2014

The colour of litmus in a neutral medium is

Apurple

Bpink

Cyellow

Dorange

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Question 20

jamb 2014

The basicity of CH₃COOH is

View Explanation & Discuss

Question 21

jamb 2014

The major and most effective way of controlling pollution is to

Aimprove machinery so that the substances released from combustion are less harmful

Bpass strict laws against it by individuals and companies

Ceducate people on the causes and effects of pollution

Dconvert chemical wastes to harmless substances before releasing them into the environment

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Question 22

jamb 2014

The dispersion of a liquid in a liquid medium will give

Aan emulsion

Ba fog

Ca gel

Dan aerosol

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Question 23

jamb 2014

16.55g of lead (ll) trioxonitrate (V) was dissolved in 100g of distilled water at 20oC, calculate the solubility of the solute in moldm-3

[Pb = 207, N = 14, O = 16]

A0.05 g

B2.00 g

C1.00 g

D0.50g

View Explanation & Discuss

Question 24

jamb 2014

On exposure to the atmosphere, a hydrated salt loses its water of crystallization to become anhydrous. This phenomenon is referred to as

Aefflorescence

Bdeliquescence

Chygroscopy

Dhydrolysis

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Question 25

jamb 2014

Water is said to be temporarily hard when it contains

ACa (HCO₃)₂ and Mg (HCO₃)₂ salts

BCa (HCO₃)₂ and CaCO₃ SALTS

CMg(HCO₃)₂ and CaSO₄ salts

DCaSO₄ and Ca(HCO₃)₂ salts

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Question 26

jamb 2014

A silicon -containing ore has 92% 28Si, 5% 29Si and 3% 30Si. Calculate the relative atomic mass of the silicon.

A14.00

B29.00

C28.11

D28.00

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Question 27

jamb 2014

The radio active radiation used in studying the arrangement of particles in giant organic molecules is

A\(\gamma\)- rays

B\(\alpha\)- particles

CX-rays

D\(\beta\) - particles

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Question 28

jamb 2014

How many protons, neutrons and electrons respectively are present in the element 60/27 Co?

A27, 33 and 33

B33, 27 and 27

C27, 33, and 27

D60, 33 and 60

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Question 29

jamb 2014

If the difference in electronegativity of elements P and Q is 3.0. The bond that will be formed between them is

Ametallic

Bcovalent

Cco-ordinate

Dionic

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Question 30

jamb 2014

Beryllium and aluminum have similar properties because they?

Aare both metals

Bbelong to the same group

Cbelong to the same period

Dare positioned diagonally to each other

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