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Chemistry Past Questions

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88 questions JAMB 2505 WAEC 1623 NECO 168 CUSTOM 10

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88 questions

Question 1 of 20 88 total questions

Question 31

jamb 1994

Which of these metals CANNOT replace hydrogen from alkaline solutions?

AAlulinium

BZinc

CTin

DIron

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Question 32

jamb 1994

Which of the following are produced when ammonium trioxonitrate (V) crystals are cautiously heated in a hard glass round bottomed flask?

AN₂O and steam

BNO₂ and ammonia

CN₂O₂ and NO₂

DNO and NO₂

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Question 33

jamb 1994

Which of the following is TRUE of Le Chatelier's Principle for an exothermic reaction?

AIncrease in temperature will cause an increase in the equilibrium constant

BIncrease in temperature will cause a decrease in the equilibrium constant

CAddition of a catalyst will cause an increase in the equilibrium constant

DAddition of a catalyst will cause a decrease in the equilibrium constant

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Question 34

jamb 1994

MnO_4(aq) + 8H + _(aq) + 5Fe²⁺ → Mn^2+(aq) + 4H₂O_(I). The oxidation number of manganese in the above reaction changed from?

A+7 to +2

B+6 to +2

C+5 to +2

D+4 to +2

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Question 35

jamb 1994

An anhydride is an oxide of non-mental

Awhich will not dissolve in water

Bwhose solution in water has a pH greater than 7

Cwhose solution in water has a pH less than 7

Dwhose solution in water has a pH of 7

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Question 36

jamb 1994

H^- + H_2(I)O → H_2(g) + OH^-_(aq). From the equation above, it can be inferred that the?

Areaction is a double decomposition

Bhydride ion is a reducing agent

Chydride ion is an oxidizing agent

Dreaction is neutralization

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Question 37

jamb 1994

Crude copper could be purified by the electrolysis of concentrated copper (II) chloride if the crude copper is?

Amade both the anode and the cathode

Bmade the cathode

Cmade the anode

Ddissolved in the solution

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Question 38

jamb 1994

What volume of Oxygen measured at s.t.p would be liberated on electrolysis by 9650 coulombs of electricity?
(Molar volume of gas = 22.4 dm\(^3\), 1F = 96,500 C/mol)

A22.4 dm³

B11.2 dm³

C1.12 dm³

D0.560 dm³

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Question 39

jamb 1994

20 cm\(^3\) of a 2.0 M solution of ethanoic acid was added to excess of 0.05 M sodium hydroxide. The mass of the salt produced is?

(Na = 23, C = 12, O = 16, H = 1)

A2.50 g

B2.73 g

C3.28 g

D4.54 g

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Question 40

jamb 1994

Which of the following compounds is a base?

ACO₂

BCaO

CH₃PO₃

DCH₃COOCH₃

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Question 41

jamb 1994

A few drops of concentrated HCI are added to about 10cm3 of a solution of pH 3.4. The pH of the resulting mixtures is?

Aless than 3.4

Bgreater than 3.4

Cunaltered

Dthe same as that of pure water

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Question 42

jamb 1994

Which of the following atoms represents deuterium?

ANo protons = 1, No of neutrons = 0, No of electrons = 0

BNo protons = 1, No of neutrons = 0, No of electrons = 1

CNo protons = 1, No of neutrons = 1, No of electrons = 1

DNo protons = 1, No of neutrons = 2, No of electrons = 1

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Question 43

jamb 1994

The solubility, in moles per dm3 of 20.2 g of potassium trioxonitrate (V) dissolve in 100 g of the resulting mixture is?

(K = 39, O = 16, N =14).

A0.10

B0.20

C1.00

D2.00

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Question 44

jamb 1994

Sodium chloride has no solubility product value because of its?

Asaline nature

Bhigh solubility

Clow solubility

Dinsolubility

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Question 45

jamb 1994

A major effect of oil pollution in coastal waters is the?

Adestruction of marine life

Bdesalination of the water

Cincrease in the acidity of the water

Ddetoxification of the water

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Question 46

jamb 1994

A solid that absorbs water from he atmosphere and forms an aqueous solution is?

Ahydrophilic

Befforescent

Cdeliquescent

Dhygroscopic

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Question 47

jamb 1994

Element X, Y and Z belong to a groups I, V and VII respectively. Which of the following is TRUE about the bond types of XZ and YZ₃?

ABoth are electrovalent

BBoth are covalent

CXZ is electrovalent and YZ₃ is covalent

DXZ is covalent and YZ₃ is electrovalent

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Question 48

jamb 1994

Which of the following physical properties decreases down a group in the periodic table?

AAtomic radius

BIonic radius

CElectropositivity

DElectronegativity

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Question 49

jamb 1994

The number of electrons in the valence shell of an element of atomic number 14 is?

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Question 50

jamb 1994

An increase in temperature causes an increase in the pressure of a gas because?

Ait decreases the number of collision between the molecules

Bthe molecules of the gas bombard the walls of the container more frequently

Cit increases the number of collision between the molecules

Dit causes the molecules to combine

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