Chemistry Exam Questions for SS2 First Term with Answers

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 SS2 First 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 YouTube. (Subscribe to the Channel)

Introduction to Chemistry as a School Subject

Before we venture into Past Chemistry Exam Questions for SS2 First term, here’s a brief introduction to the subject:

Chemistry is one of the core science subjects taught in secondary schools. It deals with the study of the composition, structure, properties, and changes of matter. In simple terms, Chemistry helps students understand what materials are made of, how they interact, and why they behave the way they do.

As a school subject, Chemistry builds a bridge between Physics and Biology. It explains many natural and industrial processes such as respiration, combustion, rusting, fermentation, and the manufacture of everyday materials like soap, fertilizers, plastics, and drugs.

Through practical experiments and theoretical lessons, students learn important scientific skills such as observation, measurement, problem-solving, and critical thinking. The knowledge of Chemistry also prepares students for careers in Medicine, Engineering, Agriculture, Pharmacy, and Environmental Science.

In summary, Chemistry is the science of substances and their transformations — a subject that helps us understand the world around us and equips students with the foundation for technological and scientific advancement.

Chemistry Exam Questions for SS2 First Term

Chemistry Exam Questions for SS2 First 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 SS2 Chemistry First Term Exam Past Questions made available to assist students in their revision for 1st term examinations and also teachers in structuring standard examinations.

SECTION A: Objective Test

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

1. Combustion is a chemical reaction that is always accompanied by
A. heat only
B. light only
C. heat and light
D. heat and sound

2. The approximate percentage of nitrogen in atmospheric air is
A. 21%          B. 78%
C. 0.97%       D. 0.03%

3. Which of the following gases burns with a blue flame?
A. Hydrogen
B. Carbon monoxide
C. Methane
D. Ethyne

4. When the supply of air is limited during combustion, one of the following is formed:
A. Carbon(IV) oxide
B. Carbon(II) oxide
C. Steam
D. Sulphur dioxide

5. The isotope of hydrogen commonly known as heavy hydrogen is
A. Protium         B. Deuterium
C. Tritium           D. Hydronium

6. Which of the following methods is not used in the manufacture of hydrogen gas?
A. Electrolysis of acidified water
B. Action of steam on red-hot coke
C. Action of steam on methane using nickel catalyst
D. Decomposition of ammonium chloride

7. Oxygen in air can be absorbed by passing it through
A. Caustic soda solution
B. Fused calcium chloride
C. Alkaline pyrogallol
D. Concentrated sulphuric acid

8. The most abundant element in the earth’s crust is
A. Nitrogen        B. Oxygen
C. Silicon            D. Carbon

9. Chlorine is a poisonous greenish-yellow gas which is
A. Denser than air
B. Insoluble in water
C. Non-poisonous
D. Easily liquefied

10. The bleaching action of chlorine in water is due to
A. Its oxidizing power
B. Its reducing property
C. Its acidic nature
D. Its ability to form oxides

11. The extraction of sulphur from the earth’s crust is carried out by the
A. Frasch process
B. Contact process
C. Solvay process
D. Haber process

12. The allotrope of sulphur that has amber colour and needle-shaped crystals is
A. Rhombic sulphur
B. Plastic sulphur
C. Monoclinic sulphur
D. Flower of sulphur

13. Nitrogen combines directly with metals except
A. Copper        B. Magnesium
C. Calcium       D. Aluminium

14. In ammonia, nitrogen has an oxidation state of
A. +3          B. -3
C. +2          D. -2

15. The oxidation number of nitrogen in magnesium nitride (Mg₃N₂) is
A. -3           B. +3
C. 0             D. +2

16. Which of the following statements about nitrogen(IV) oxide is incorrect?
A. It is a reddish-brown gas
B. It has a pungent odour
C. It is not poisonous
D. It is heavier than air

17. Ammonia is used for all of the following purposes except
A. As a fertilizer
B. In refrigeration
C. As a cleansing agent
D. As a food preservative

18. The physical properties of nitrogen include the following except
A. It is colourless and odourless
B. It is slightly soluble in water
C. It turns moist red litmus blue
D. It does not support combustion

19. The following are members of the halogen family except
A. Fluorine        B. Chlorine
C. Astatine        D. Barium

20. Which of the following gases rekindles a glowing splint?
A. Hydrogen      B. Oxygen
C. Nitrogen        D. Chlorine

21. The main constituent of natural gas is
A. Methane      B. Ethane
C. Propane       D. Butane

22. Which of the following best describes oxidation?
A. Loss of hydrogen
B. Gain of electrons
C. Gain of oxygen
D. Combination with water

23. A substance that can act as both acid and base is called
A. Neutral compound
B. Amphoteric substance
C. Alkaline compound
D. Basic salt

24. Which of the following oxides is neutral?
A. Carbon(II) oxide
B. Sodium oxide
C. Sulphur dioxide
D. Nitrogen dioxide

25. Which of the following acids is used in car batteries?
A. Hydrochloric acid
B. Nitric acid
C. Sulphuric acid
D. Acetic acid

26. Which of the following is a strong electrolyte?
A. Dilute HCl
B. Glucose solution
C. Ethanol
D. Distilled water

27. A molecule that contains both ionic and covalent bonds is
A. Sodium chloride
B. Ammonium chloride
C. Carbon dioxide
D. Hydrogen gas

28. The atomic number of an element represents the number of
A. Neutrons in its nucleus
B. Protons in its nucleus
C. Electrons and neutrons
D. Nucleons in the atom

29. The horizontal rows in the periodic table are called
A. Groups        B. Periods
C. Families       D. Blocks

30. Elements in the same group of the periodic table have
A. The same atomic number
B. The same number of protons
C. The same number of valence electrons
D. The same number of neutrons

31. Which of the following is a property of covalent compounds?
A. High melting point
B. High electrical conductivity
C. Insolubility in organic solvents
D. Poor electrical conductivity

32. Which of the following pairs of elements will form an ionic compound?
A. Hydrogen and oxygen
B. Sodium and chlorine
C. Nitrogen and hydrogen
D. Carbon and sulphur

33. Which of the following statements about catalysts is correct?
A. They alter the equilibrium position
B. They are used up in the reaction
C. They increase the rate of reaction
D. They increase the activation energy

34. Which of the following gases turns lime water milky?
A. Carbon dioxide
B. Nitrogen
C. Oxygen
D. Sulphur dioxide

35. Temporary hardness in water can be removed by
A. Boiling
B. Addition of slaked lime
C. Filtration
D. Freezing

36. A mixture of gases can best be separated by
A. Distillation
B. Filtration
C. Fractional distillation
D. Evaporation

37. The law of conservation of mass was proposed by
A. Dalton
B. Boyle
C. Lavoisier
D. Gay-Lussac

38. Which of the following is not a characteristic of chemical change?
A. Formation of new substance
B. It is easily reversible
C. Evolution of gas
D. Change in colour

39. The most electronegative element is
A. Oxygen         B. Chlorine
C. Nitrogen       D. Fluorine

40. The pH of a neutral solution at room temperature is
A. 0           B. 7
C. 10         D. 14

41. The oxidation number of sulphur in H₂SO₄ is
A. +2         B. +4
C. +6         D. +8

42. The reaction between acid and base to form salt and water is called
A. Decomposition
B. Neutralization
C. Oxidation
D. Reduction

43. Which of the following metals will react with cold water?
A. Sodium      B. Magnesium
C. Iron            D. Copper

44. The gas used in the Haber process is
A. Hydrogen       B. Oxygen
C. Ammonia       D. Nitrogen

45. A liquid which has a definite volume but no definite shape is held together by
A. Cohesive forces
B. Adhesive forces
C. Gravitational force
D. Nuclear force

46. The colour of the flame produced by burning sodium is
A. Blue        B. Yellow
C. Red         D. Green

47. The process of converting solid directly to gas is called
A. Evaporation
B. Condensation
C. Sublimation
D. Crystallization

48. Which of the following gases can decolourize acidified potassium permanganate?
A. Hydrogen
B. Oxygen
C. Sulphur dioxide
D. Nitrogen

49. Which of the following pairs of substances are allotropes?
A. O₂ and O₃
B. H₂ and H₂O
C. CO and CO₂
D. N₂ and NO₂

50. When an element gains electrons, it becomes
A. Neutral      B. Cation
C. Anion         D. Proton

51. Which of the following is a noble gas?
A. Argon        B. Chlorine
C. Fluorine     D. Oxygen

52. The colour of litmus in an acidic solution is
A. Red         B. Blue
C. Pink        D. Colourless

53. Which of the following elements is a transition metal?
A. Sodium       B. Calcium
C. Iron             D. Potassium

54. The compound formed when hydrogen reacts with chlorine is
A. Hydrogen chloride
B. Hydrogen chlorate
C. Hydrochloric acid
D. Hydrogen peroxide

55. The first element in Period 3 of the periodic table is
A. Sodium       B. Magnesium
C. Argon          D. Aluminium

56. Which of the following methods can be used to collect oxygen in the laboratory?
A. Upward delivery
B. Downward delivery
C. Over water
D. Over mercury

57. Which of the following is not a property of metals?
A. Good conductor of heat
B. Ductility
C. Brittleness
D. Malleability

58. Which of the following pairs are acid and base respectively?
A. NaOH and H₂SO₄
B. HCl and NaOH
C. H₂SO₄ and H₂O
D. NH₃ and H₂O

59. A catalyst used in the contact process is
A. Iron
B. Vanadium(V) oxide
C. Nickel
D. Platinum

60. Which of the following statements about acids is true?
A. They taste bitter
B. They turn blue litmus red
C. They are soapy to touch
D. They neutralize bases to form hydrogen gas

SECTION B: Essay / Theory

INSTRUCTION – Answer only five (5) questions in this section. Write your answers clearly and show working where necessary.

1. (a) List the main constituents of atmospheric air and state their approximate percentage composition.

(b) With the aid of a diagram, show the fractional composition of air.

2. (a) Name three allotropes of sulphur and describe how each can be prepared in the laboratory.
(b) Mention four uses of sulphur or its compounds.

3. (a) Describe the laboratory preparation of ammonia gas.
(b) State three chemical properties of ammonia.

4. (a) Explain the industrial preparation of oxygen by fractional distillation of liquid air.
(b) List three physical properties, two chemical properties, and two uses of oxygen.

5. (a) Define acids, bases, and salts, giving one example of each.
(b) Explain the neutralization reaction between hydrochloric acid and sodium hydroxide, using a chemical equation.

6. (a) Explain the term oxidation and reduction in terms of electron transfer.
(b) Give two examples each of oxidizing and reducing agents.

7. (a) Define chemical bonding and explain the difference between ionic and covalent bonding.
(b) Using suitable examples, show how sodium chloride and water molecules are formed.

Remember to use the comments sections if you have questions, and don’t forget to join our Free Online Tutorial Classes on YouTube. (Subscribe to the Channel)

Answers to Chemistry Exam Questions for SS2 First Term

Answers to Section A (Objective Test)

The following table gives the correct answers to the objective section of Chemistry exam questions for SS2 First 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 SS2 First 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)

Answers to Question 1.

(a) The main constituents of atmospheric air and their approximate percentage composition are:

• Nitrogen – 78%
• Oxygen – 21%
• Argon – 0.93%
• Carbon dioxide – 0.03%
• Other gases (neon, krypton, xenon, etc.) – traces

(b) Fractional composition of air can be shown by the diagram below:

Diagram: (Vertical column showing gases separated by fractional distillation of liquid air — nitrogen at the top, oxygen in the middle, argon and other gases at the bottom.)

Answers to Question 2.

(a) The three allotropes of sulphur are:

• Rhombic sulphur (α-sulphur): Prepared by crystallizing molten sulphur at room temperature. It is yellow, crystalline, and stable at room temperature.
• Monoclinic sulphur (β-sulphur): Formed by cooling molten sulphur slowly to about 96°C and allowing it to crystallize. It changes to rhombic form at room temperature.
• Plastic sulphur: Obtained by pouring boiling sulphur into cold water. It is soft, elastic, and turns brittle on standing.

(b) Uses of sulphur or its compounds:

• Used in the manufacture of sulphuric acid.
• Usëd in vulcanization of rubber.
• Used in making matches and gunpowder.
• Used in making fungicides and insecticides.

Answers to Question 3.

(a) Laboratory preparation of ammonia gas:

Ammonia gas is prepared by heating a mixture of ammonium chloride and slaked lime in a flask.

Chemical equation: 2NH₄Cl + Ca(OH)₂ → 2NH₃ + CaCl₂ + 2H₂O

The gas is collected by the downward displacement of air since it is lighter than air.

(b) Chemical properties of ammonia:

• It is basic and reacts with acids to form salts.
• ït reacts with oxygen to form nitrogen and water.
• It combines with hydrogen chloride gas to form white fumes of ammonium chloride.

Answers to Question 4.

(a) Industrial preparation of oxygen by fractional distillation of liquid air:

Air is first cleaned, compressed, and cooled to form liquid air. The liquid air is then fractionally distilled. Nitrogen, having a lower boiling point (-196°C), distills off first, while oxygen (boiling point -183°C) is collected later as a liquid and stored.

(b) Physical properties of oxygen:

• It is a colourless, odourless gas.
• ït supports combustion.
• It is slightly soluble in water.

Chemical properties:

• It reacts with elements to form oxides.
• It supports burning of fuels like hydrogen, sulphur, and carbon.

Uses:

• Used in hospitals for respiration.
• Used in welding and cutting metals.

Answers to Question 5.

(a) Definitions and examples:

• Acid: A substance that produces hydrogen ions (H⁺) in solution. Example: HCl.
• Base: A substance that produces hydroxide ions (OH⁻) in solution. Example: NaOH.
• Salt: A compound formed when the hydrogen of an acid is replaced by a metal or ammonium ion. Example: NaCl.

(b) Neutralization reaction:

When hydrochloric acid reacts with sodium hydroxide, salt and water are formed.

Chemical equation: HCl + NaOH → NaCl + H₂O

Answers to Question 6.

(a) Oxidation and reduction in terms of electron transfer:

• Oxidation is the loss of electrons by a substance.
• Reduction is the gain of electrons by a substance.

Example: Na → Na⁺ + e⁻ (oxidation), Cl₂ + 2e⁻ → 2Cl⁻ (reduction)

(b) Examples of agents:

• Oxidizing agents: potassium permanganate (KMnO₄), chlorine (Cl₂)
• Reducing agents: hydrogen (H₂), carbon monoxide (CO)

Answers to Question 7.

(a) Definition and difference:

Chemical bonding is the force of attraction that holds atoms together in compounds.

• Ionic bond: Formed by transfer of electrons from one atom to another, producing oppositely charged ions. Example: NaCl.
• Covalent bond: Formed by sharing of electrons between atoms. Example: H₂O.

(b) Examples:

Sodium chloride (NaCl): Formed when sodium donates one electron to chlorine.

Na → Na⁺ + e⁻; Cl + e⁻ → Cl⁻; Na⁺ + Cl⁻ → NaCl

Water (H₂O): Formed when oxygen shares electrons with two hydrogen atoms.

H • + O •• → H–O–H (shared electron pairs form covalent bonds).

Read Also: Chemistry Exam Questions for SS1 First Term with Answers

How to Pass Chemistry Exam Questions for SS2 First Term

Passing your Chemistry exam questions for SS2 First term requires a combination of preparation, understanding, and strategy. Here are actionable tips to help you excel:

1. Know the syllabus.Check topics set for the term. Focus on them first. Don’t waste time on off-syllabus items.
2. Make a study plan.Break topics into small parts. study one part each day. Include time for revision and practice.
3. Understand ideas — don’t just memorise.Learn why reactions happen. Practice writing equations until they become natural.
4. Memorise key facts and formulas.Write important numbers, gas tests, and formulas on a single sheet. Read it daily.
5. Practice past questions.Do real exam questions under timed conditions. Mark yourself and learn from mistakes.
6. Master practical skills.Know common lab procedures, observations and safety points. Practical questions often come in theory form.
7. Answering objective questions (MCQs).Read the stem carefully. Cover the options and think of an answer first. Then confirm with the choices.
8. Answering theory questions.Start with a short definition. Use numbered points. Give equations where needed. Finish with a short conclusion.
9. Draw clear diagrams.Label parts neatly. A neat diagram can earn marks fast. Practice common diagrams: apparatus, fractionating column, electron dot structures.
10. Show your working.For calculations, write each step. Examiners give marks for method even if the final number is slightly wrong.
11. Manage your time in the exam.Answer easy questions first. Allocate time for each section. Leave 10 minutes at the end to check your paper.
12. Use correct units and significant figures.Avoid losing marks for missing units. Give answers to the required number of significant figures when asked.
13. Keep neat handwriting.Illegible answers may be misunderstood. Write clearly and use paragraphs or bullet points.
14. Stay calm and rest well.Sleep the night before. Eat a light breakfast. A calm mind thinks better.
15. After the exam.Check the paper and learn from errors. Make a note of areas to improve for next time.

Work every day. Practice with purpose. You will pass if you prepare well.

It’s a wrap!

If you need more clarification on SS2 First Term Questions on Chemistry, you can use the comments box below. We’ll be there to answer you asap. Don’t forget to join our Free Online Tutorial Classes on YouTube. (Subscribe to the Channel)

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