CHEMISTRY PAST QUESTIONS APP - 2023

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SSCE/NECO/GCE (CHEMISTRY PAST QUESTIONS)

CHEMISTRY PAST QUESTIONS APP

Questions will be picked at random from the question bank.
You can use the NEXT button to move to the next question, use the PREV button to move to the previous question, the CLEAR button to clear any answer of your choice and you have the FINISH button to end the exam if you choose to.
Any question not answered before the end of the exam time, will be marked as wrong and the exam will end by itself. so try to attempt all questions on time.
Goodluck!

1 / 80

Category: CHEMISTRY PAST QUESTIONS

What volume of hydrogen is produced at s.t.p. When 2.60 g of zinc reacts with excess HCI according to the following equation? Zn_(s) + 2HCI_(aq) → ZnCI _2(aq) + H_2(g) [Zn = 65; 1 mole of a gas occupies 22.4dm³ at s.t.p]

5.82dm 3

0.896dm 3

8.62dm 3

0.040dm 3

2 / 80

Category: CHEMISTRY PAST QUESTIONS

What is the function of sulphur (IV) oxide in the reaction represented by the following equation? SO _2(aq) + 2H₂S_(g) → 3S _(s) + 2H ₂O _(l)

Acid

Oxidising agent

Bleaching agent

Dehydrating agent

3 / 80

Category: CHEMISTRY PAST QUESTIONS

Equal volumes of CO₂ cnd CO at s.t.p have the same

density

mass

number of molecules

rate of diffusion

4 / 80

Category: CHEMISTRY PAST QUESTIONS

The presence of unpaired electrons in an atom of a transition metal gives rise to

ductility

paramagnetism

shiny appearance

nalleability

5 / 80

Category: CHEMISTRY PAST QUESTIONS

A concentrated solution containing H⁺, Cu²⁺,OH^- and CI^- was electrolysed using platiunm electrodes which of the ions will be discharged at the cathods?

CI-

OH-

Cu2+

H+

6 / 80

Category: CHEMISTRY PAST QUESTIONS

Exhaust fumes discharged from a smoky vehicle gradually become invisible as a result of

combustion

emission

absorption

diffusion

7 / 80

Category: CHEMISTRY PAST QUESTIONS

Elactrostatic force of attraction between sodium ion and halide ion is greatest in

NaCI

NaBr

NaI

NaF

8 / 80

Category: CHEMISTRY PAST QUESTIONS

Which of the following movements can be described as random motion?

wheelbarrow being pushed

car travelling on a straight line

planets going round the sun

gas molecules colliding in a flask

9 / 80

Category: CHEMISTRY PAST QUESTIONS

The type of chemical bond that exists between potassium and oxygen in potassium oxide is

ionic

metallic

dative

covalent

10 / 80

Category: CHEMISTRY PAST QUESTIONS

What does ∆H represent in the following equation ? Cl_(g) + e- → CI- _(g); ∆H = - 363 kJ mol-¹

Dissociation energy

Heat of atomization

lonization energy

Electron affinity

11 / 80

Category: CHEMISTRY PAST QUESTIONS

Pipe-borne water is usually chlorinated in order to

improve the teste of the water

remove the hardness in the water clear

coagulate sediments in the water

kill harmful bacteria in the water

12 / 80

Category: CHEMISTRY PAST QUESTIONS

The property of calcium chloride which makes it useful as a drying agent is that it is

deliquescent

a strong electrolyte

a normal salt

ionic

13 / 80

Category: CHEMISTRY PAST QUESTIONS

What will be the effect of increase in pressure on the following system at equilibrium? 2NH_2(g) N_2(g) + 3H_2(g)

the reaction will go to completion

the forward reaction will be favoured

Activation energy will decrease

the concentration of ammonia will increase

14 / 80

Category: CHEMISTRY PAST QUESTIONS

What mass of copper would be deposited by a current of 1. 0 ampere passing for 965 seconds through copper (ll) tetraoxosulphate (IV) solution? [Cu = 63.5; 1F = 96500C]

0.635g

0.318g

18g

6.35g

15 / 80

Category: CHEMISTRY PAST QUESTIONS

Helium is preferred to hydrogen in filling balloons because hydrogen

is inflammable

is a component of water

exhibits isotopy

is diatomic

16 / 80

Category: CHEMISTRY PAST QUESTIONS

Electrovalent compounds are characterized by

strong oxidizing ability

high melting point

high molar mass

solubility in ethanol

17 / 80

Category: CHEMISTRY PAST QUESTIONS

The atoms of four elements are represented as ₂₀Q, ₁₆R, ₁₀S and ₈T Which of the elements would be unreactive?

R

Q

T

S

18 / 80

Category: CHEMISTRY PAST QUESTIONS

P _Total = F₁ + P₂ + P ₃ + .........P_n' where P _Total is the pressure of a mixture of gasses. The equation above is an expression of

Graham's law

Gay-Lussac's Law

Dalton's law

Boyle's law

19 / 80

Category: CHEMISTRY PAST QUESTIONS

What is the effect of using vanadium (V) oxide as catalyst in the reaction represented by the following equation? 2SO₂ + O₂ ⇌ 2SO₃; ∆H = - xKJmol-¹

Reduces the time for attainment of equilibrium

Shifts equilibrium position to the right

Increases the collision rate of reactant particles

Decreases the value of ∆H

20 / 80

Category: CHEMISTRY PAST QUESTIONS

Which of the following contains co-ordinate covalent bond?

Na+CI

HCI

CH4

NH4

21 / 80

Category: CHEMISTRY PAST QUESTIONS

In the Periodic Table, the elements that loss electrons most readily belong to

Group 111 A

Group 11 A

Group V11 A

Group 1 A

22 / 80

Category: CHEMISTRY PAST QUESTIONS

Which of the following statements about ideal gases is/are correct?
I. The cohesive forces between their particles are negligible
ll. The have no definite volume but occupy the volume of their containers
III. They are not compressible
IV. Their particles collide with loss of energy

l and ll only

l, ll, lll, and IV

l, ll and lll only

l only

23 / 80

Category: CHEMISTRY PAST QUESTIONS

Chlorine atom forms CI by

Losing one electron

Donating lone pair of electrons

Sharing one electron

Gaining one electron

24 / 80

Category: CHEMISTRY PAST QUESTIONS

Rusting of iron is an example of

displacement reaction

decomposition

redox reaction

deliquescence

25 / 80

Category: CHEMISTRY PAST QUESTIONS

What type of reaction is involved when wood shavings produce a brown gas with concentrated HNO₃?

Destructive distillation

Nutralization

Dehydration

Redox reaction

26 / 80

Category: CHEMISTRY PAST QUESTIONS

0.10 mol dm^-3 NaCI conducts electricity better than 0.10 mol dm^-3 CH₃COOH because the solution of NaCI

has a higher pH

is neutral to litmus

contains more ions

has a lower molar mass

27 / 80

Category: CHEMISTRY PAST QUESTIONS

A reaction is represented by the equation below. A_2(g) + B_2(g) 2AB_(g); ∆H = +X kJmol^-1 Which of the following statements about the system is correct?

The reaction goes to completion at equilibrium

Pressure has no effect on the equilibrium mixture

The forward reaction is exthermic

At equilibrium increase in temperature favours the reverse reaction

28 / 80

Category: CHEMISTRY PAST QUESTIONS

Which of the following lowers the activation energy of a chemical reaction?

Water

Reducing agent

Freezing mixture

Catalyst

29 / 80

Category: CHEMISTRY PAST QUESTIONS

Aluminium is extracted from

magnetite

cassiterite

cryolite

bauxite

30 / 80

Category: CHEMISTRY PAST QUESTIONS

Which of the following pairs of reagents recat to produce hydrogen?

Water and calcium dicarbide

Copper and dilute hydrochloric acid

Zinc and concentrated trioxonitrate (V) acid

Magnesium and dilute tetraoxosulphate (VI) acid

31 / 80

Category: CHEMISTRY PAST QUESTIONS

A mixture of calcium chloride and calcium trioxocarbonate (IV) in water can be separated by

sublimation

evaporation

distillation

filtration

32 / 80

Category: CHEMISTRY PAST QUESTIONS

How many electrons are removed from Cr^2- when it is oxidized to CrO₄^2-?

8

2

4

0

33 / 80

Category: CHEMISTRY PAST QUESTIONS

Which of the following substances decomposes when an electric current is passed through it?

Tetrachlormethane

Hydrochloric acid

Zinc rod

Glucose solution

34 / 80

Category: CHEMISTRY PAST QUESTIONS

Which of the following would dissolve in warm dilute H₂SO₄ without effervescence, to give a blue solution?

Copper (ll) oxide

Copper (ll) trioxocarbonate (IV)

Copper turnings

Copper alloy

35 / 80

Category: CHEMISTRY PAST QUESTIONS

Gas molecules are said to be perfectly elastic because

they collide without loss of energy

the distances between them are negligible

the volume occupied by them is negligible

they move about in straight lines

36 / 80

Category: CHEMISTRY PAST QUESTIONS

An exothermic reaction is one which involves

evolution of gas as it proceeds

positive change in value of enthalpy

loss of heat to the surrounding

attainment of dynamic equilibrium

37 / 80

Category: CHEMISTRY PAST QUESTIONS

What is the value of x in the following equation? Cr₂O₇^2- + 14H⁺ + xe- → 2Cr³⁺ + 7H₂O

12

6

1

8

38 / 80

Category: CHEMISTRY PAST QUESTIONS

If the solubility of KHCO₃ is 0.40 mole dm^-3

10.0g

100.0g

40.0g

4.0g

39 / 80

Category: CHEMISTRY PAST QUESTIONS

What is oxidized in the reaction represented by the following equation? 3CU + 8HNO₃ → 3Cu(NO₃)₂ + 2NO + 4H₂O

Copper

Hydrogen

Nitrogen

Oxygen

40 / 80

Category: CHEMISTRY PAST QUESTIONS

Which of the following will produce oxygen and hydrogen during its electrolysis using platinum electrode?

Dilute sodium chloride solution

Aqueous copper (ll) tetraoxosulphate (IV)

Glucose solution

Concentrated hydrochloric acid

41 / 80

Category: CHEMISTRY PAST QUESTIONS

A radioactive solid is best stored

under paraffin oil

in a cool, dark cupboard

under ultraviolet light

in a box lined with lead

42 / 80

Category: CHEMISTRY PAST QUESTIONS

What is the shape of a molecule of CCI₄?

Linear

Pyramidal

Tetrahedral

Trigonal planar

43 / 80

Category: CHEMISTRY PAST QUESTIONS

What is the oxidation number of nitrogen in AI(NO₃)₃?

+ 3

+ 5

+ 1

+ 6

44 / 80

Category: CHEMISTRY PAST QUESTIONS

Which of the following will displace copper from a solution of copper (ll) salt?

Silver

Aluminium ions

Magnesium

Zinc ions

45 / 80

Category: CHEMISTRY PAST QUESTIONS

A sheet of paper is placed in the path of a beam from a radioactive source. The emissions that pass through the paper consist of

alpha particles and gamma rays

alpha particles only

beta particles and gamma rays

alpha and beta particles

46 / 80

Category: CHEMISTRY PAST QUESTIONS

Petrol consists mainly of

alkanoates

polymers

hydrocarbons

alktanols

47 / 80

Category: CHEMISTRY PAST QUESTIONS

Given that the order of reactivity of four metals is P>Q>R>S, which of the following reactions is feasible?

R + P+ → P + R+

S + P+ → P + S +

Q + S+ → S + Q+

S + Q+ → Q + S+

48 / 80

Category: CHEMISTRY PAST QUESTIONS

Which of the following compounds dissolves in water to give an alkaline solution?

Sodium chloride

Sulphur (IV) oxide

Potassium oxide

Ammonium chloride

49 / 80

Category: CHEMISTRY PAST QUESTIONS

The crystal layers in graphite are held together by

covalent bonds

electrostatic forces

van der Waals' forces

hydrogen bonds

50 / 80

Category: CHEMISTRY PAST QUESTIONS

The gas evolved when dilute tetraoxosulphate (VI) acid reacts with sodium hydrogen trioxocarbonate (IV) is

hydrogen

oxygen

carbon (IV) oxide

sulphur (VI) oxide

51 / 80

Category: CHEMISTRY PAST QUESTIONS

Chemical equilibrium is attained when

concentrations of the reactants and products remain constant

concentrations of the products are greater than those of the reactants

reactants in the system are used up

reactants stop forming the products

52 / 80

Category: CHEMISTRY PAST QUESTIONS

If an element with high electron affinity combines with another element with low ionization energy the bond formed will be mainly

dative

covalent

metallic

ionic

53 / 80

Category: CHEMISTRY PAST QUESTIONS

Which of the orbitals 4s, 4p, 4d and 4f has the lowest energy?

4f

4d

4s

4p

54 / 80

Category: CHEMISTRY PAST QUESTIONS

Metals are said to be malleable because they

are good conductors heat

can be beaten into sheets

can be alloyed

are good conductors of electricity

55 / 80

Category: CHEMISTRY PAST QUESTIONS

Which of the following can undergo both addition reactions and substitution reactions?

Hexane

Pentane

Propene

Benzene

56 / 80

Category: CHEMISTRY PAST QUESTIONS

Which of the following features of a human skeleton can be determined by carbon-dating?

Race

Height

Age

Mass

57 / 80

Category: CHEMISTRY PAST QUESTIONS

Which of the following occurs when a solution of CuSO₄ is electrolysed using copper electrodes?

Both electrodes gain electrons

The anode increases in mass

The blue colour of the solution fades gradually

The cathode becomes coated with copper

58 / 80

Category: CHEMISTRY PAST QUESTIONS

One mole of a compound M(HCO₃)₂ has a mass of 162g. Calculate the relative atomic mass of M. [H = 1, C =12, O = 16]

122

40

53

101

59 / 80

Category: CHEMISTRY PAST QUESTIONS

Which of the following procedures is suitable for identifying the food colouring added to a pastry sample?

Both electrodes gain electrons

The blue colour of the solution fades gradually

The cathode becomes coated with copper

The anode increases in mass

60 / 80

Category: CHEMISTRY PAST QUESTIONS

A finely divided from of a metal burns more readily in air than the rod from because the rod has

protective oxide coating

different chemical properties

smaller surface area

higher molar mass

61 / 80

Category: CHEMISTRY PAST QUESTIONS

Dehydration of ethanol produces

ethanal

propan-1,2,3-triol

ethanoic acid

ethene

62 / 80

Category: CHEMISTRY PAST QUESTIONS

It can be concluded that gastric juice

contains enzymes

is a mixture

has pH value of 7

is acidic

63 / 80

Category: CHEMISTRY PAST QUESTIONS

The liquid product of the destructive distillation of coal is

ethanol

kerosene

paraffin oil

ammoniacal liquor

64 / 80

Category: CHEMISTRY PAST QUESTIONS

Which of the following compounds dissolves in water to form a solution with pH below 7?

Sodium trioxocarbonate (IV)

Sodium tetraoxosulphate (VI)

Ammonium chloride

Potassium hydroxide

65 / 80

Category: CHEMISTRY PAST QUESTIONS

When alkanols react with sodium, the ga evolved is

hydrogen

ethyne

oxygen

methane

66 / 80

Category: CHEMISTRY PAST QUESTIONS

Which of the following increases as boiling water changes to steam?

activation energy

degree of disorder in the system

temperature of the system

number of molecules

67 / 80

Category: CHEMISTRY PAST QUESTIONS

The spontaneity of a chemical reaction is determined by the change in the

concentration of the reactants

temperature of the system

pressure applied to the system

free energy of the system

68 / 80

Category: CHEMISTRY PAST QUESTIONS

Which of the following methods is suitable for the preparation of an insoluble salt?

Action of an acid on a metal

Double decomposition

Action of an acid on a trioxocarbonate (IV)

Neutralisation

69 / 80

Category: CHEMISTRY PAST QUESTIONS

30cm³ pf hydrogen at s.t.p combine with 20cm³ of oxygen to form steam according to the following equation 2H_2(g) + O_2(g) → 2H₂O_(g). Calculate the total volume of the gaseous mixture at the end of the reaction

35cm cube

50cm cube

25cm cube

30cm cube

70 / 80

Category: CHEMISTRY PAST QUESTIONS

Two radioactive elements Q and S have half-life periods of 10 hours and 20 hours respectively. Therefore

S is more stable than Q

Q is twice as stable as S

S decays faster than Q

Q emits fewer particles than S

71 / 80

Category: CHEMISTRY PAST QUESTIONS

Substances which absorb water from the atmosphere without dissolving in it are said to be

anhydrous

hygroscopic

insolube

hydrated

72 / 80

Category: CHEMISTRY PAST QUESTIONS

Which of the following is not correct about oxidation number convention? The oxidation number of a/an

atom of a diatomic molecules is + 2

alkali meta like sodium in its compounds is + 1

element in the free state is zero

monatomic ion is equal to its charge

73 / 80

Category: CHEMISTRY PAST QUESTIONS

What is responsible for metallic bonding?

Attraction between the atomic unclei and cloud of electrons

transfer of electrons from one atom to another

Sharing of electrons between the metal atoms

Attraction between positive and negative ions

74 / 80

Category: CHEMISTRY PAST QUESTIONS

Which of the following non-metals reacts most readily with metals?

Nitrogen

Carbon

Sulphur

Chlorine

75 / 80

Category: CHEMISTRY PAST QUESTIONS

Calcium atom ionizes by

sharing two electrons

gaining two electrons

gaining two protons

losing two electrons

76 / 80

Category: CHEMISTRY PAST QUESTIONS

Consider the reaction represented by the following equation: H_2(g) + 1_2(g) → 2HI_(g). The number of effective collisions of molecules of the reactants decreases as

the pressure increased

the volume of the system is increased

a catalysty is intoduced into the system

the temperature is raised

77 / 80

Category: CHEMISTRY PAST QUESTIONS

Pauli Exclusion Principle is related to

electronegativity values of elements

reversiblility of equlibrium reactions

quantum numbers of electrons

collision theory of reaction rates

78 / 80

Category: CHEMISTRY PAST QUESTIONS

Elements which belong to the same group in the Periodic Table are characterized by

difference of 14 atomic mass units between successive members

presence of the same number of electron shells in the respective atoms

difference of +1 in the oxidation numbers of successive members

presence of the same number of outermost electrons in the respective atoms

79 / 80

Category: CHEMISTRY PAST QUESTIONS

Which of the following properties increases down a group in the Periodic Table?

Electon affinity

Atomic radius

Ionization energy

Electronegativity

80 / 80

Category: CHEMISTRY PAST QUESTIONS

Consider the following equation: Ag⁺ _(aq) + CI-_(aq) → Ag⁺CI- _(s) ; ∆H = _65.7 kJmol^-1. From the equation, it can be deduced that

activation energy is high and a catalyst is required

direct combination is involved and the reaction is endothermic

the reaction is endothermic and occurs at high temperature

a solid is formed and heat is evolved

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