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SSCE/NECO/GCE (CHEMISTRY PAST QUESTIONS)

CHEMISTRY PAST QUESTIONS

Attempt all 60 questions that are selected from the Chemistry question bank. Use the NEXT, PREV, CLEAR and FINISH buttons to navigate around the CBT.

You have 1 hour to answer all 60 questions.

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1 / 60

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

Increases the collision rate of reactant particles

Decreases the value of ∆H

Shifts equilibrium position to the right

Reduces the time for attainment of equilibrium

2 / 60

Category: CHEMISTRY PAST QUESTIONS

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

planets going round the sun

wheelbarrow being pushed

gas molecules colliding in a flask

car travelling on a straight line

3 / 60

Category: CHEMISTRY PAST QUESTIONS

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

Concentrated hydrochloric acid

Dilute sodium chloride solution

Aqueous copper (ll) tetraoxosulphate (IV)

Glucose solution

4 / 60

Category: CHEMISTRY PAST QUESTIONS

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

Glucose solution

Hydrochloric acid

Tetrachlormethane

Zinc rod

5 / 60

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]

101

122

40

53

6 / 60

Category: CHEMISTRY PAST QUESTIONS

Electrovalent compounds are characterized by

solubility in ethanol

high melting point

high molar mass

strong oxidizing ability

7 / 60

Category: CHEMISTRY PAST QUESTIONS

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

Catalyst

Water

Reducing agent

Freezing mixture

8 / 60

Category: CHEMISTRY PAST QUESTIONS

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

a normal salt

a strong electrolyte

ionic

deliquescent

9 / 60

Category: CHEMISTRY PAST QUESTIONS

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

Sulphur

Chlorine

Nitrogen

Carbon

10 / 60

Category: CHEMISTRY PAST QUESTIONS

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

Q is twice as stable as S

Q emits fewer particles than S

S decays faster than Q

S is more stable than Q

11 / 60

Category: CHEMISTRY PAST QUESTIONS

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

Oxygen

Copper

Nitrogen

Hydrogen

12 / 60

Category: CHEMISTRY PAST QUESTIONS

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

The blue colour of the solution fades gradually

The anode increases in mass

Both electrodes gain electrons

The cathode becomes coated with copper

13 / 60

Category: CHEMISTRY PAST QUESTIONS

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

number of molecules

rate of diffusion

mass

density

14 / 60

Category: CHEMISTRY PAST QUESTIONS

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

difference of +1 in the oxidation numbers of successive members

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

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

difference of 14 atomic mass units between successive members

15 / 60

Category: CHEMISTRY PAST QUESTIONS

Petrol consists mainly of

polymers

alkanoates

alktanols

hydrocarbons

16 / 60

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 lower molar mass

is neutral to litmus

contains more ions

has a higher pH

17 / 60

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

metallic

dative

covalent

ionic

18 / 60

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)

Bleaching agent

Acid

Oxidising agent

Dehydrating agent

19 / 60

Category: CHEMISTRY PAST QUESTIONS

Chlorine atom forms CI by

Sharing one electron

Gaining one electron

Losing one electron

Donating lone pair of electrons

20 / 60

Category: CHEMISTRY PAST QUESTIONS

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

hydrated

hygroscopic

insolube

anhydrous

21 / 60

Category: CHEMISTRY PAST QUESTIONS

An exothermic reaction is one which involves

positive change in value of enthalpy

attainment of dynamic equilibrium

evolution of gas as it proceeds

loss of heat to the surrounding

22 / 60

Category: CHEMISTRY PAST QUESTIONS

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

paramagnetism

ductility

shiny appearance

nalleability

23 / 60

Category: CHEMISTRY PAST QUESTIONS

What is the shape of a molecule of CCI₄?

Pyramidal

Tetrahedral

Trigonal planar

Linear

24 / 60

Category: CHEMISTRY PAST QUESTIONS

Chemical equilibrium is attained when

concentrations of the products are greater than those of the reactants

reactants in the system are used up

reactants stop forming the products

concentrations of the reactants and products remain constant

25 / 60

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-

H+

Cu2+

OH-

26 / 60

Category: CHEMISTRY PAST QUESTIONS

It can be concluded that gastric juice

has pH value of 7

contains enzymes

is a mixture

is acidic

27 / 60

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

beta particles and gamma rays

alpha particles only

alpha and beta particles

alpha particles and gamma rays

28 / 60

Category: CHEMISTRY PAST QUESTIONS

Rusting of iron is an example of

redox reaction

displacement reaction

decomposition

deliquescence

29 / 60

Category: CHEMISTRY PAST QUESTIONS

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

T

R

S

Q

30 / 60

Category: CHEMISTRY PAST QUESTIONS

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

diffusion

combustion

absorption

emission

31 / 60

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?

Q + S+ → S + Q+

R + P+ → P + R+

S + Q+ → Q + S+

S + P+ → P + S +

32 / 60

Category: CHEMISTRY PAST QUESTIONS

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

The blue colour of the solution fades gradually

Both electrodes gain electrons

The cathode becomes coated with copper

The anode increases in mass

33 / 60

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]

0.896dm 3

0.040dm 3

5.82dm 3

8.62dm 3

34 / 60

Category: CHEMISTRY PAST QUESTIONS

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

Age

Mass

Race

Height

35 / 60

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 alloy

Copper turnings

Copper (ll) trioxocarbonate (IV)

36 / 60

Category: CHEMISTRY PAST QUESTIONS

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

Heat of atomization

Dissociation energy

lonization energy

Electron affinity

37 / 60

Category: CHEMISTRY PAST QUESTIONS

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

Hexane

Benzene

Pentane

Propene

38 / 60

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 only

l, ll and lll only

l and ll only

l, ll, lll, and IV

39 / 60

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 forward reaction will be favoured

the reaction will go to completion

Activation energy will decrease

the concentration of ammonia will increase

40 / 60

Category: CHEMISTRY PAST QUESTIONS

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

Group 11 A

Group 111 A

Group V11 A

Group 1 A

41 / 60

Category: CHEMISTRY PAST QUESTIONS

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

dative

metallic

ionic

covalent

42 / 60

Category: CHEMISTRY PAST QUESTIONS

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

1

12

8

6

43 / 60

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 forward reaction is exthermic

At equilibrium increase in temperature favours the reverse reaction

Pressure has no effect on the equilibrium mixture

The reaction goes to completion at equilibrium

44 / 60

Category: CHEMISTRY PAST QUESTIONS

A radioactive solid is best stored

under ultraviolet light

in a cool, dark cupboard

under paraffin oil

in a box lined with lead

45 / 60

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 temperature is raised

a catalysty is intoduced into the system

the volume of the system is increased

the pressure increased

46 / 60

Category: CHEMISTRY PAST QUESTIONS

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

Electon affinity

Ionization energy

Atomic radius

Electronegativity

47 / 60

Category: CHEMISTRY PAST QUESTIONS

When alkanols react with sodium, the ga evolved is

ethyne

oxygen

hydrogen

methane

48 / 60

Category: CHEMISTRY PAST QUESTIONS

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

oxygen

sulphur (VI) oxide

hydrogen

carbon (IV) oxide

49 / 60

Category: CHEMISTRY PAST QUESTIONS

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

+ 6

+ 5

+ 3

+ 1

50 / 60

Category: CHEMISTRY PAST QUESTIONS

Gas molecules are said to be perfectly elastic because

the distances between them are negligible

they collide without loss of energy

they move about in straight lines

the volume occupied by them is negligible

51 / 60

Category: CHEMISTRY PAST QUESTIONS

Metals are said to be malleable because they

are good conductors of electricity

can be alloyed

are good conductors heat

can be beaten into sheets

52 / 60

Category: CHEMISTRY PAST QUESTIONS

Which of the following contains co-ordinate covalent bond?

NH4

Na+CI

HCI

CH4

53 / 60

Category: CHEMISTRY PAST QUESTIONS

Pipe-borne water is usually chlorinated in order to

kill harmful bacteria in the water

remove the hardness in the water clear

improve the teste of the water

coagulate sediments in the water

54 / 60

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

Boyle's law

Graham's law

Gay-Lussac's Law

Dalton's law

55 / 60

Category: CHEMISTRY PAST QUESTIONS

The crystal layers in graphite are held together by

hydrogen bonds

van der Waals' forces

covalent bonds

electrostatic forces

56 / 60

Category: CHEMISTRY PAST QUESTIONS

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

Silver

Zinc ions

Magnesium

Aluminium ions

57 / 60

Category: CHEMISTRY PAST QUESTIONS

The liquid product of the destructive distillation of coal is

kerosene

ethanol

ammoniacal liquor

paraffin oil

58 / 60

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

direct combination is involved and the reaction is endothermic

a solid is formed and heat is evolved

the reaction is endothermic and occurs at high temperature

activation energy is high and a catalyst is required

59 / 60

Category: CHEMISTRY PAST QUESTIONS

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

Magnesium and dilute tetraoxosulphate (VI) acid

Zinc and concentrated trioxonitrate (V) acid

Copper and dilute hydrochloric acid

Water and calcium dicarbide

60 / 60

Category: CHEMISTRY PAST QUESTIONS

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

100.0g

40.0g

10.0g

4.0g

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