CHEMISTRY PAST QUESTIONS

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.

Goodluck

1 / 60

Category: CHEMISTRY PAST QUESTIONS

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

Reducing agent

Freezing mixture

Catalyst

Water

2 / 60

Category: CHEMISTRY PAST QUESTIONS

Rusting of iron is an example of

deliquescence

decomposition

redox reaction

displacement reaction

3 / 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?

S + P+ → P + S +

Q + S+ → S + Q+

S + Q+ → Q + S+

R + P+ → P + R+

4 / 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 reaction goes to completion at equilibrium

The forward reaction is exthermic

Pressure has no effect on the equilibrium mixture

At equilibrium increase in temperature favours the reverse reaction

5 / 60

Category: CHEMISTRY PAST QUESTIONS

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

Zinc and concentrated trioxonitrate (V) acid

Copper and dilute hydrochloric acid

Water and calcium dicarbide

Magnesium and dilute tetraoxosulphate (VI) acid

6 / 60

Category: CHEMISTRY PAST QUESTIONS

Gas molecules are said to be perfectly elastic because

they collide without loss of energy

the volume occupied by them is negligible

they move about in straight lines

the distances between them are negligible

7 / 60

Category: CHEMISTRY PAST QUESTIONS

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

different chemical properties

smaller surface area

protective oxide coating

higher molar mass

8 / 60

Category: CHEMISTRY PAST QUESTIONS

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

Hexane

Propene

Pentane

Benzene

9 / 60

Category: CHEMISTRY PAST QUESTIONS

The liquid product of the destructive distillation of coal is

ammoniacal liquor

ethanol

paraffin oil

kerosene

10 / 60

Category: CHEMISTRY PAST QUESTIONS

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

Electon affinity

Ionization energy

Electronegativity

Atomic radius

11 / 60

Category: CHEMISTRY PAST QUESTIONS

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

diffusion

emission

combustion

absorption

12 / 60

Category: CHEMISTRY PAST QUESTIONS

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

4p

4s

4d

4f

13 / 60

Category: CHEMISTRY PAST QUESTIONS

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

Ammonium chloride

Potassium hydroxide

Sodium trioxocarbonate (IV)

Sodium tetraoxosulphate (VI)

14 / 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 concentration of ammonia will increase

the forward reaction will be favoured

the reaction will go to completion

Activation energy will decrease

15 / 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

8.62dm 3

5.82dm 3

0.040dm 3

16 / 60

Category: CHEMISTRY PAST QUESTIONS

Aluminium is extracted from

cryolite

magnetite

cassiterite

bauxite

17 / 60

Category: CHEMISTRY PAST QUESTIONS

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

Mass

Height

Age

Race

18 / 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

activation energy is high and a catalyst is required

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

19 / 60

Category: CHEMISTRY PAST QUESTIONS

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

Destructive distillation

Redox reaction

Nutralization

Dehydration

20 / 60

Category: CHEMISTRY PAST QUESTIONS

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

Potassium oxide

Ammonium chloride

Sodium chloride

Sulphur (IV) oxide

21 / 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

Shifts equilibrium position to the right

Reduces the time for attainment of equilibrium

Increases the collision rate of reactant particles

Decreases the value of ∆H

22 / 60

Category: CHEMISTRY PAST QUESTIONS

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

insolube

hydrated

anhydrous

hygroscopic

23 / 60

Category: CHEMISTRY PAST QUESTIONS

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

0

4

2

8

24 / 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

The cathode becomes coated with copper

The anode increases in mass

Both electrodes gain electrons

25 / 60

Category: CHEMISTRY PAST QUESTIONS

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

planets going round the sun

gas molecules colliding in a flask

car travelling on a straight line

wheelbarrow being pushed

26 / 60

Category: CHEMISTRY PAST QUESTIONS

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

+ 5

+ 6

+ 3

+ 1

27 / 60

Category: CHEMISTRY PAST QUESTIONS

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

ductility

nalleability

shiny appearance

paramagnetism

28 / 60

Category: CHEMISTRY PAST QUESTIONS

The crystal layers in graphite are held together by

electrostatic forces

covalent bonds

hydrogen bonds

van der Waals' forces

29 / 60

Category: CHEMISTRY PAST QUESTIONS

Petrol consists mainly of

polymers

alktanols

alkanoates

hydrocarbons

30 / 60

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

Neutralisation

Action of an acid on a trioxocarbonate (IV)

Double decomposition

31 / 60

Category: CHEMISTRY PAST QUESTIONS

Helium is preferred to hydrogen in filling balloons because hydrogen

is diatomic

is a component of water

exhibits isotopy

is inflammable

32 / 60

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]

18g

0.635g

6.35g

0.318g

33 / 60

Category: CHEMISTRY PAST QUESTIONS

What is responsible for metallic bonding?

Attraction between the atomic unclei and cloud of electrons

Sharing of electrons between the metal atoms

Attraction between positive and negative ions

transfer of electrons from one atom to another

34 / 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

covalent

dative

metallic

ionic

35 / 60

Category: CHEMISTRY PAST QUESTIONS

Chlorine atom forms CI by

Sharing one electron

Losing one electron

Gaining one electron

Donating lone pair of electrons

36 / 60

Category: CHEMISTRY PAST QUESTIONS

It can be concluded that gastric juice

is a mixture

is acidic

has pH value of 7

contains enzymes

37 / 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?

OH-

Cu2+

H+

CI-

38 / 60

Category: CHEMISTRY PAST QUESTIONS

An exothermic reaction is one which involves

evolution of gas as it proceeds

attainment of dynamic equilibrium

positive change in value of enthalpy

loss of heat to the surrounding

39 / 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 volume of the system is increased

the temperature is raised

a catalysty is intoduced into the system

the pressure increased

40 / 60

Category: CHEMISTRY PAST QUESTIONS

When alkanols react with sodium, the ga evolved is

ethyne

oxygen

hydrogen

methane

41 / 60

Category: CHEMISTRY PAST QUESTIONS

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

free energy of the system

temperature of the system

pressure applied to the system

concentration of the reactants

42 / 60

Category: CHEMISTRY PAST QUESTIONS

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

hydrogen

sulphur (VI) oxide

carbon (IV) oxide

oxygen

43 / 60

Category: CHEMISTRY PAST QUESTIONS

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

metallic

dative

ionic

covalent

44 / 60

Category: CHEMISTRY PAST QUESTIONS

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

Dissociation energy

lonization energy

Electron affinity

Heat of atomization

45 / 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

46 / 60

Category: CHEMISTRY PAST QUESTIONS

Pipe-borne water is usually chlorinated in order to

kill harmful bacteria in the water

improve the teste of the water

coagulate sediments in the water

remove the hardness in the water clear

47 / 60

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

30cm cube

25cm cube

50cm cube

48 / 60

Category: CHEMISTRY PAST QUESTIONS

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

evaporation

sublimation

filtration

distillation

49 / 60

Category: CHEMISTRY PAST QUESTIONS

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

NaBr

NaI

NaCI

NaF

50 / 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

The cathode becomes coated with copper

Both electrodes gain electrons

51 / 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

alpha particles only

alpha particles and gamma rays

alpha and beta particles

beta particles and gamma rays

52 / 60

Category: CHEMISTRY PAST QUESTIONS

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

Group V11 A

Group 1 A

Group 111 A

Group 11 A

53 / 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 and ll only

l, ll, lll, and IV

l, ll and lll only

54 / 60

Category: CHEMISTRY PAST QUESTIONS

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

Copper (ll) trioxocarbonate (IV)

Copper alloy

Copper (ll) oxide

Copper turnings

55 / 60

Category: CHEMISTRY PAST QUESTIONS

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

degree of disorder in the system

number of molecules

activation energy

temperature of the system

56 / 60

Category: CHEMISTRY PAST QUESTIONS

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

Copper

Oxygen

Hydrogen

Nitrogen

57 / 60

Category: CHEMISTRY PAST QUESTIONS

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

8

1

12

6

58 / 60

Category: CHEMISTRY PAST QUESTIONS

Metals are said to be malleable because they

can be alloyed

can be beaten into sheets

are good conductors heat

are good conductors of electricity

59 / 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]

122

101

40

53

60 / 60

Category: CHEMISTRY PAST QUESTIONS

Which of the following contains co-ordinate covalent bond?

NH4

CH4

Na+CI

HCI

Your score is

0%

SCHOOL PORTAL NG

Author: School Portal NG

Leave a Reply Cancel reply

Search For Anything

Subjects/Courses

Join 3,000,000 Learners

Most Viewed Lessons

Useful Links

Products

Recent Comments

Join Over 3,000,000 Learners

Useful Links

Follow School Portal NG

Our Sites

INSTALL TO YOUR HOME SCREEN!