Chemistry Exam Questions for SS1 Third Term

You’re welcome to our school exams series where we provide you with termly examination questions in different subjects. In today’s post, we will focus on Chemistry exam questions. We will cover Chemistry exam questions for SS1 Third term with answers. This means that we’ll be providing you with answers to the questions at the end. Also, you will get a few success tips on how to pass Chemistry examinations with flying colors. Remember to use the comments sections if you have questions, and don’t forget to join our Free Online Tutorial Classes on Facebook. (Like and Follow Page)

Introduction to Chemistry as a School Subject

Chemistry is the branch of science that deals with the structure, composition, and properties of substances, as well as the changes they undergo during chemical reactions. It helps students understand the nature of matter and how different elements combine to form compounds.

As a school subject, Chemistry is essential for students who wish to pursue careers in medicine, pharmacy, engineering, and other science-related fields. It teaches practical skills through laboratory experiments and promotes critical thinking and problem-solving abilities.

Studying Chemistry also helps students understand everyday phenomena such as cooking, cleaning, rusting, and even breathing. It is a vital subject that connects science with daily life and technological advancement.

The subject is offered by students in Senior Secondary School as Chemistry.

Chemistry Exam Questions for SS1 Third Term

Chemistry Exam Questions for SS1 Third Term are divided into two sections:

• Section A
• Section B

The first section, namely, Section A is the objective test, and students are expected to attempt all questions in the section. Section B is the theory part, and students are expected to follow specific instruction and answer the required number of questions.

Note that what you have below are SS1 Chemistry Third Term Exam Past Questions made available to assist students in their revision for 3rd term examinations and also teachers in structuring standard examinations.

SECTION A: Objectives

Instruction: Answer all questions in this section by choosing from the options lettered A—D. Each question carries equal marks.

1. The shape of carbon (IV) oxide molecule is
A. Linear          B. Tetrahedral
C. Angular       D. Pyramidal

2. The oxidation state of bromine in HBrO₃ is
A. 1          B. 3
C. 5          D. 7

3. The electronic configuration 1s² 2s² 2p³ contravenes the
A. Pauli exclusion
B. Hund’s rule
C. Octet rule
D. Aufbau principle

4. Bases are normally
A. corrosive
B. turn litmus paper red to blue
C. turn litmus paper blue to red
D. are non-metal oxides

5. Pairs of outermost shell electrons which are not used in bonding are
A. lone pairs
B. bond pairs
C. valence electrons
D. shared pairs

6. ^2-₈X and ₁₀Y are
A. Isotopes           B. Allotropes
C. Isoelectronic    D. Isomers

7. Pure water contaminated with quicklime will have a pH of
A. 1          B. 6
C. 7          D. 8

8. How many covalent bonds are formed by nitrogen gas?
A. 1          B. 2
C. 3          D. 4

9. When an element exists in two or more forms in the same physical state, it exhibits
A. Isotopes          B. Allotropes
C. Isobars            D. Isomerism

10. Naturally occurring boron is made up of 19.9% boron of mass number 10 and 80.1% boron of mass number 11. The relative atomic mass of boron is
A. 21.0            B. 10.8
C. 10.0            D. 11

11. The number of shared pair of electrons in a molecule of CH₄ is
A. 2          B. 4
C. 6          D. 8

12. Isotopes of the same element have the same chemical properties because they have the same number of
A. protons          B. neutrons
C. atoms             D. ions

13. An atom of an element in the ground state contains eight valence electrons The element is considered as a
A. metal             B. semi-metal
C. noble gas       D. halogen

14. Consider the reaction represented by the equation: C₃H₈ + 50₂ → 3CO₂ + 6H₂O. If 0.1 mol of C₃H₈ was completely burnt, what volume of CO₂ would be produced at stp? (Molar Volume = 22.4dm³)
A. 6.72dm³           B. 2.24dm³
C. 0.30dm³           D. 0.10dm³

15. The volume of 22g of CO₂ at stp is equivalent to _______ (C = 12, O = 16, Molar Volume at stp = 22.4dm³)
A. 22.0dm³          B. 22.4dm³
C. 11.2dm³          D. 5.6dm³

16. The hardest form of carbon is
A. charcoal        B. Coke
C. Diamond       D. Graphite

17. A given quantity of gas occupies a volume of 228cm³ at a pressure of 750mmHg. What will be its volume at atmospheric pressure?
A. 230cm³            B. 225cm³
C. 230cm³            D. 231cm³

18. In a mixture of gases which do not react chemically together, the pressure exerted by the individual gases is called
A. Partial pressure
B. Atmospheric pressure
C. Vapour pressure
D. Total pressure

19. What volume of steam will be produced, if 400cm3 of ethane is completely burnt in excess oxygen according to the equation: 2C₂H₆ + 7O_2(g) → 4CO_2(g) + 6H₂O_(g)
A. 200cm³          B. 400cm³
C. 600cm³          D. 1200cm³

20. The density of a certain gas is 1.98gdm^-3 at stp. What is the molar mass of the gas?
A. 54.0           B. 44.0
C. 31.0           D. 26.0

21. Which of the following gases has vapour density of 17? (H=1,C=12, N=14, O=16, S=32, Cl=35.5)
A. Cl₂           B. H₂S
C. NH₃         D. CO

22. Which of the following expressions correctly represents Charles’ law?
A. PV = k         B. PV = T
C. V = KT         D. R = V

23. Which of the following gases has the highest rate of diffusion under the same conditions?
A. O₂            B. Cl₂
C. HCl           D. SO₂

24. What is the ratio of the rate of diffusion of CO₂ to that of C₃H₈ under similar conditions?
A. 2:1           B. 1:2
C. 1:1           D. 2:3 (H=1, O=16, C=12)

25. A gas X diffuses twice as fast as gas Y under similar conditions If the relative molecular mass of X is 28, calculate the relative molecular mass of Y.
A. 14         B. 56
C. 112       D. 120

26. A hydrocarbon with vapour density 22 contains 36g of carbon. What is its molecular formula? (C=12, H=1)
A. C₂H₄          B. C₂H₆
C. C₃H₆          D. C₃H₈

27. Deviation of a gas from ideal behaviour is maximum at
A. low temperature and high pressure
B. high temperature and low pressure
C. high temperature and high pressure
D. low temperature and low pressure

28. Consider: Cu²⁺ + 4H₂O → (Cu(H₂O)₄)²⁺. The bond between copper (ii) ion and water molecules is
A. electrovalent         B. covalent
C. coordinate             D. metallic

29. The presence of sugar particles in ice will
A. decrease the boiling point
B. increase the boiling point
C. lower the melting point
D. increase the melting point

30. The following compounds are formed by covalent bond except
A. HBr           B. HCI
C. NaH          D. NH₃

31. If 20cm³ of hydrogen combine with 20cm³ of oxygen according to the equation: 2H_2(g)+ O_2(g) → 2H₂O_(g). Calculate the volume of the gaseous mixture at the end of the reaction.
A. 50cm³          B. 35cm³
C. 30cm³          D. 25cm³

32. Calculate the mass of chlorine gas which occupies a volume of 1.12dm³ at stp. (Cl = 35.5, molar volume = 22.4dm³)
A. 1.8g          B. 3.55g
C. 7.10g        D. 15.5g

33. Calculate the amount of a gas which occupies 250cm³ at stp.
A. 0.112mol        B. 0.12mol
C. 0.11mol          D. 0.2mol

34. What is the concentration of NaOH solution containing 6.0g in 250cm³ solution (Na=40, O=16, H=1)
A. 0.04moldm^-3        B. 0.6moldm^-3
C. 0.96dm^-3              D. 0.15dm^-3

35. Which of the following compounds is not a double salt?
A. Zn(OH)NO₃
B. KAI(SO₄)₂
C. KCr(SO₄)₂
D. (NH₄)Fe(SO₄)₂

36. Which of the following is a complex salt?
A. Na₂SO₄           B. Mg(OH)Cl
C. K₄Fe(CN)₆        D. KMnO₄

37. Which of the following acids forms normal salt only?
A. H₂SO₄         B. HCl
C. H₃PO₄         D. H₂SO₄

38. When sodium trioxocarbonate (iv) decahydrate loses its water of crystallization to the atmosphere, the process is
A. efflorescence
B. Deliquescence
C. Hygroscopic
D. Effervescence

39. The percentage of water of crystallization in ZnSO₄.7H₂O is
A. 33%         B. 44%
C. 55%         D. 87%
(Zn=65, S=32, O=16, H=1).

40. The salt formed from a reaction between citric acid and sodium hydroxide, in solution will be
A. Acidic           B. Basic
C. Neutral         D. Complex

41. A solution of pH 5 is
A. acidic           B. basic
C. neutral         D. saturated

42. Which of the following is NOT a general method of preparing acids?
A. Dissolution of hydroxides
B. Direct combination of constituent elements
C. Dissolution of acid anhydride in water
D. Using a strong acid to displace a weak acid from its salt.

43. Vapour pressure of a liquid depends on I. temperature II. cohesive forces holding the particles III. rate of condensation.
A. I B. I and II
C. II and III D. I, II and III

44. The following acids are monobasic except
A. Tetraoxosulphate (vi) acid
B. Ethanoic acid
C. Hydrochloric acid
D. Hydrofluoric acid

45. P_total = P₁ + P₂ + P₃ ……. + P_n is an expression of
A. Dalton’s law
B. Graham’s law
C. Boyle’s law
D. Charles’ law

46. The bond pair of electrons in a hydrogen fluoride molecule is pulled towards the Fluorine atom because
A. Fluorine is more electronegative
B. Fluorine has a larger atomic size
C. Fluorine has a larger atomic mass
D. There is no bond between hydrogen and fluorine

47. The energy released when an isolated gaseous atom gains an electron is known as
A. Ionization energy
B. Electronegativity
C. Electron affinity
D. Bond energy

48. The shape of diamond crystals is
A. Tetrahedral         B. Octahedral
C. Hexagonal          D. Pyramidal

49. Which of the following acid will not liberate hydrogen gas when react with a metal?
A. Trioxocarbonate (iv) acid
B. Trioxonitrate (v) acid
C. Hydrochloric acid
D. Tetraoxosulphate vi acid

50. What is the total pressure of a mixture containing 0.1dm³ of oxygen gas and 0.9dm³ of nitrogen gas [Molar volume=22.4dm³, R=0.082atmdm³k^-1mol^-1] A. 1atm           B. 9.0atm
C. 0.1atm        D. 0.9atm

51. Assuming pressure is constant, at which temperature will the volume of a gas become twice of what it was at 10°C?
A. 273k         B. 546k
C. 566k         D. 564k

52. According to Charles’ law, the volume of a gas becomes zero at
A. -100°C        B. -273°C
C. 273°C         D. 100°C

53. Chemicals which are produced in small quantities and with very high degree of purity are
A. Bulk chemicals
B. Heavy chemicals
C. Fine chemicals
D. Light chemicals

54. Which of the following raw materials is used in the plastic industry?
A. Calcium         B. Hydrogen
C. Ethene           D. Methane

55. The following are heavy chemicals except
A. Tetraoxosulphate (vi) acid
B. Caustic soda
C. Dyes
D. Sodium trioxocarbonate (iv)

56. How many electrons are present in ₄Be²⁺?
A. 6          B. 4
C. 2          D. 1

57. The most suitable method to use when separating an insoluble solid from a liquid is
A. Evaporation       B. Decantation
C. Filtration            D. Sublimation

58. If the atomic number of an element X is 11, and that of nitrogen is 7. The most likely formula of the nitride of X is
A. X₃N₂        B. X₃N
C. XN₃         D. XN₂

59. In bonded atoms, increase in electronegativity difference
A. increases polarity
B. decreases polarity
C. has no effect on polarity
D. brings polarity to zero

60. A sample of fruit juice has pH of 4.2. What is the concentration in moldm^-3 of the hydrogen ion in the juice?
A. 6.3 x 10^-5
B. 1.58 x 10^-3
C. 1.58 x 10^-10

SECTION B: Essay

INSTRUCTION – Answer all five (5) questions in this section.

1. Consider the following table:

Which of the elements:
i. is in group Vll?
ii. is in period 4?
iii. would readily form an ion with a double negative charge?
iv. How many protons and neutrons are there in the nucleus of Q?

b. i. What type of bond would exist between M and O when they combine together?
ii. What force of attraction would hold molecules of M and O together?
iii. Define the force mentioned in b. ii.

c. i. Write the formula of the compound formed when P combines with N.
ii. Give two general characteristics of the compound formed between M and Q.

2. a. i. Define vapour density.
ii. If 300cm³ of hydrogen gas was collected over water at 27°C and 780mmHg, calculate the volume of the dry gas at stp. (S.V.P of water at 27°C is 10mmHgss).
iii. Sketch a graph to represent Boyle’s law

b. i. Explain why an inflated balloon expands in warm water.
ii. State two assumptions of the kinetic theory of gases.
iii. State two reasons why real gases deviate from ideal gas behavior.

3. a. State Gay-Lussac’s law of combining volumes.

b. Carbon(ii) oxide reacted with oxygen to form carbon (iv) oxide in a sealed tube:
i. Write a balanced equation for the reaction.
ii. If 40cm³ of carbon (ii) were mixed with 30cm³ of oxygen, calculate the volume of the residual gases at the end of the reaction.
iii. State two differences between boiling and evaporation.

c. A sample of methane gas CH₄ is burnt at a rate of 0.8g per second for 30 minutes to produce carbon (iv) oxide and steam:
i. Write a balanced equation for the reaction.
ii. Determine the volume of carbon (iv) oxide produced
iii. Determine the number of moles of oxygen used up in the process (C=12, H=1, O=16, molar volume=22.4dm³).

4. a. Define the following terms:
i. Strong acid
ii. Weak acid
iii. Efflorescence
iv. Deliquescence

b. i. Define lewis acid and base.
ii. Give One example of a Lewis acid and one example of a Lewis base

C. i. Define salt
ii. Explain two methods of preparing salts and give One equation for each method

Answers to Chemistry Exam Questions for SS1 Third Term

Answers to Section A (Objective Test)

The following table gives the correct answers to the objective section of Chemistry exam questions for SS1 Third term. If you are using a mobile device, hold the table and scroll to the right or left for a complete view.

So here you have the answers to the objective section of Chemistry Exam Questions for SS1 Third term. Use the comments section to let me know if you have any questions you would want me to clarify or discuss further.

Answers to Section B (Theory)

1. Based on the given table:

i. The element in Group VII is O (Atomic number 9).
ii. The element in Period 4 is Q (Atomic number 19).
iii. The element that would readily form an ion with a double negative charge is N (Oxygen – Atomic number 8).
iv. The number of protons in Q = 19; Number of neutrons = 39 – 19 = 20.

b.
i. The type of bond between M (Hydrogen) and O (Fluorine) is a covalent bond.
ii. The force of attraction between molecules of M and O is van der Waals force.
iii. Van der Waals force is a weak intermolecular force that occurs between molecules due to temporary dipoles induced in them.

c.
i. Formula of compound when P (Aluminum) combines with N (Oxygen) is Al₂O₃.
ii. Two general characteristics of compound formed between M and Q:
– It has high melting and boiling points.
– It conducts electricity when dissolved in water or molten (ionic compound).

2. a.

i. Vapour density is defined as the mass of a certain volume of a gas compared to the mass of an equal volume of hydrogen gas under the same conditions of temperature and pressure.

ii. Correction of pressure: 780 mmHg – 10 mmHg = 770 mmHg
Using Boyle’s law:
P₁V₁ = P₂V₂
770 × 300 = 760 × V₂
V₂ = (770 × 300) / 760 = 303.95 cm³ (approx)

iii. Graph for Boyle’s law: A curve showing an inverse relationship between pressure and volume at constant temperature.

b.
i. An inflated balloon expands in warm water because the gas molecules inside the balloon move faster when heated, increasing pressure and volume.
ii. Two assumptions of the kinetic theory of gases:
– Gases consist of particles in constant, random motion.
– There are no attractive or repulsive forces between the gas particles.
iii. Two reasons real gases deviate from ideal behavior:
– Presence of intermolecular forces.
– Volume occupied by the gas molecules is not negligible.

3. a.

Gay-Lussac’s law states that when gases react, they do so in volumes that bear a simple ratio to each other and to the volumes of the products, provided temperature and pressure remain constant.

b.
i. 2CO(g) + O₂(g) → 2CO₂(g)
ii. 2 volumes of CO react with 1 volume of O₂
40 cm³ CO : 30 cm³ O₂
Required: 40 cm³ CO needs 20 cm³ O₂ → Leaves 10 cm³ O₂ unused
Residual gases = 10 cm³ (O₂)
iii. Differences between boiling and evaporation:
– Boiling occurs at a fixed temperature, while evaporation occurs at any temperature.
– Boiling is a bulk process; evaporation is a surface phenomenon.

c.
i. CH₄ + 2O₂ → CO₂ + 2H₂O
ii. Mass of CH₄ = 0.8g × 30 × 60 = 1440g
Molar mass of CH₄ = 12 + (4 × 1) = 16g
Moles of CH₄ = 1440 / 16 = 90 moles
Volume of CO₂ = 90 × 22.4 = 2016 dm³
iii. Moles of O₂ = 90 × 2 = 180 moles

4. a.

i. Strong acid: An acid that completely ionizes in solution.
ii. Weak acid: An acid that partially ionizes in solution.
iii. Efflorescence: The loss of water of crystallization from a hydrated salt when exposed to air.
iv. Deliquescence: The process by which a substance absorbs moisture from the air and dissolves in it.

b.
i. A Lewis acid is a substance that accepts an electron pair; a Lewis base is a substance that donates an electron pair.
ii. Example of Lewis acid: AlCl₃
Example of Lewis base: NH₃

c.
i. A salt is a compound formed when the hydrogen ion in an acid is replaced by a metal or ammonium ion.
ii. Two methods of preparing salts:
– Neutralization: Acid + Base → Salt + Water
Example: HCl + NaOH → NaCl + H₂O
– Precipitation: Mixing two solutions to form an insoluble salt
Example: AgNO₃ + NaCl → AgCl↓ + NaNO₃

Read Also: Geography Exam Questions for SS1 Third Term

How to Pass Chemistry Exam Questions for SS1 Third Term

Passing your Chemistry exam questions for SS1 Third term requires a combination of preparation, understanding, and strategy. Here are actionable tips to help you excel:

1. Understand Basic Concepts: Pay close attention to key topics like chemical bonding, periodic table, acids and bases, gas laws, and atomic structure. Understanding these foundations will help you solve both theory and calculations with ease.

2. Practice Calculations: Topics like mole concept, molar volume, vapour density, and Boyle’s law often involve calculations. Practice different questions regularly to master the formulas and steps.

3. Memorize Important Definitions and Laws: Chemistry contains many definitions, laws, and properties. Ensure you can define terms like valency, ionization energy, efflorescence, and state laws like Boyle’s and Charles’ law clearly.

4. Study with Past Questions: Review previous exam questions for third term. This helps you know the common question patterns and how to answer them correctly.

5. Do Practical Revisions: Chemistry involves experiments. Revise your notes on practical activities and ensure you understand how to record observations, write equations, and draw apparatus.

6. Stay Focused and Avoid Cramming: Chemistry is best understood, not crammed. Read daily, take short notes, and ask your teacher for clarification when needed.

With discipline and consistent study, you will pass your SS1 third term Chemistry exam successfully.

It’s a wrap!

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Best wishes.