ICSE Class 9 Chemistry · Exam Practice

Chemistry Practice Paper — Set 1

Chemistry Practice Paper — Set 1. ICSE Class 9 Chemistry, covering the language of chemistry, chemical changes, atomic structure and bonding, the periodic table, gas laws, water, hydrogen and atmospheric pollution, with a full answer key and worked solutions.

🎯 Full Marks: 50⏱️ Time: 1½ Hours📝 Questions: 30
SectionType of questionsQsMarks
AMultiple Choice Questions1010
BFill in the Blanks & True / False88
CShort Answer Questions816
DProblem Solving416
Total3050
Before you start
  • This paper samples across the ICSE Class 9 Chemistry chapters on MuskMeadow: the language of chemistry, chemical changes, atomic structure and bonding, the periodic table, gas laws, water, hydrogen and atmospheric pollution.
  • Attempt the paper first, without looking at the answer key at the bottom of the page.
  • Show your working for Sections C and D — method marks are given even if the final answer is wrong.
  • This is a MuskMeadow practice paper. It is not an official CISCE paper and its mark scheme does not copy the board's exact pattern.
10 MARKS

Section A — Multiple Choice Questions

Choose the correct option. (1 mark each)

1. The number of electrons in a sodium ion (Na⁺, atomic number 11) is

A. 11B. 10C. 12D. 9

2. The valency of magnesium (atomic number 12, configuration 2, 8, 2) is

A. 1B. 2C. 3D. 4

3. A gas occupies 6 L at 2 atm. At the same temperature its volume at 3 atm is

A. 9 LB. 4 LC. 12 LD. 2 L

4. 0°C on the Kelvin scale is approximately

A. 0 KB. 100 KC. 273 KD. 373 K

5. Hydrogen is prepared in the laboratory by the action of dilute sulphuric acid on

A. copperB. zincC. silverD. gold

6. Water has its maximum density at

A. 0°CB. 4°CC. 100°CD. −4°C

7. An element with the electronic configuration 2, 8, 7 belongs to

A. Group 1B. Group 7 (17)C. Group 2D. Group 18

8. Which of these is a chemical change?

A. Melting of iceB. Rusting of ironC. Dissolving sugar in waterD. Boiling of water

9. In the balanced equation 2H₂ + O₂ → 2H₂O, the coefficient of water is

A. 1B. 2C. 3D. 4

10. Acid rain is mainly caused by

A. SO₂ and NO₂B. N₂ and O₂C. He and NeD. H₂ and CH₄
8 MARKS

Section B — Fill in the Blanks & True / False

Fill in each blank, or write True / False. (1 mark each)

11. Mass number = number of protons + number of ______.

12. The relative molecular mass of water (H = 1, O = 16) is ______.

13. Isotopes of an element have the same number of neutrons. (   )

14. Hydrogen burns in air with a pale blue flame. (   )

15. In an ionic bond, electrons are ______ from one atom to another.

16. Elements in the same group of the periodic table have the same number of ______ electrons.

17. Carbon dioxide turns lime water milky. (   )

18. The most abundant gas in the air is ______.

16 MARKS

Section C — Short Answer Questions

Show your working. (2 marks each)

19. Write the electronic configuration of chlorine (atomic number 17).

20. Balance: Fe + O₂ → Fe₂O₃.

21. Calculate the molecular mass of CO₂ (C = 12, O = 16).

22. 500 mL of a gas at 1 atm is compressed to 2 atm at constant temperature. Find the new volume.

23. Write the formula of sodium chloride and name the type of bond in it.

24. State two physical properties of hydrogen.

25. Why does ice float on water?

26. Give two harmful effects of acid rain.

16 MARKS

Section D — Problem Solving

Show all steps. (4 marks each)

27. An atom has atomic number 17 and mass number 35. Find (a) the number of protons, electrons and neutrons, (b) its electronic configuration and (c) its valency.

28. A gas occupies 600 mL at 27°C. Its temperature is raised to 127°C at constant pressure. Find the new volume.

29. Find the percentage composition of hydrogen and oxygen in water (H = 1, O = 16).

30. Zinc reacts with hydrochloric acid: Zn + 2HCl → ZnCl₂ + H₂. (a) What type of reaction is this? (b) Find the mass of hydrogen released from 6.5 g of zinc (Zn = 65, H = 1).

ICSE Class 9 Chemistry · Chemistry Practice Paper — Set 1 · Answer Key

Answers & Worked Solutions

Check your paper, then read the solutions for the questions you missed.

Section A — Multiple Choice Questions (10 marks)
Q1. B. 10

A sodium atom has 11 electrons; Na⁺ has lost one, so it has 10.

Q2. B. 2

Magnesium loses its 2 outer electrons, so its valency is 2.

Q3. B. 4 L

Boyle’s law: P₁V₁ = P₂V₂ ⇒ 2 × 6 = 3 × V₂ ⇒ V₂ = 4 L.

Q4. C. 273 K

K = °C + 273, so 0°C = 273 K.

Q5. B. zinc

Zn + H₂SO₄ → ZnSO₄ + H₂. Copper, silver and gold do not displace hydrogen from dilute acids.

Q6. B. 4°C

Water is densest at 4°C, which is why ice floats and lakes freeze from the top.

Q7. B. Group 7 (17)

Seven valence electrons place it in the halogen group (Group 17), e.g. chlorine.

Q8. B. Rusting of iron

Rusting forms a new substance (iron oxide), so it is a chemical change.

Q9. B. 2

Two molecules of water are formed from two molecules of hydrogen and one of oxygen.

Q10. A. SO₂ and NO₂

SO₂ and nitrogen oxides dissolve in rain water to form sulphuric and nitric acids.

Section B — Fill in the Blanks & True / False (8 marks)
Q11. neutrons

Mass number counts the particles in the nucleus: protons and neutrons.

Q12. 18

2 × 1 + 16 = 18.

Q13. False

Isotopes have the same number of protons but different numbers of neutrons.

Q14. True

Hydrogen is combustible and burns to form water; it does not support combustion.

Q15. transferred

In covalent bonding electrons are shared, in ionic bonding they are transferred.

Q16. valence (outermost)

This is why elements in a group show similar chemical properties.

Q17. True

CO₂ + Ca(OH)₂ → CaCO₃ (white, insoluble) + H₂O.

Q18. nitrogen

Air is about 78% nitrogen and 21% oxygen by volume.

Section C — Short Answer Questions (16 marks)
Q19. 2, 8, 7
  1. Chlorine has 17 electrons.
  2. K shell 2, L shell 8, M shell 17 − 10 = 7, so 2, 8, 7.
Q20. 4Fe + 3O₂ → 2Fe₂O₃
  1. Fe₂O₃ has 2 Fe and 3 O; use 2Fe₂O₃ to get an even number of O: 4 Fe and 6 O.
  2. So 4Fe + 3O₂ → 2Fe₂O₃. Check: Fe 4 = 4, O 6 = 6 ✓.
Q21. 44
  1. CO₂ has 1 C and 2 O atoms.
  2. 12 + 2 × 16 = 44.
Q22. 250 mL
  1. Boyle’s law: P₁V₁ = P₂V₂.
  2. 1 × 500 = 2 × V₂ ⇒ V₂ = 250 mL.
Q23. NaCl; ionic bond
  1. Na has valency 1 and Cl has valency 1, so the formula is NaCl.
  2. Sodium transfers one electron to chlorine, forming Na⁺ and Cl⁻, held by an ionic bond.
Q24. Colourless, odourless, lightest gas
  1. Hydrogen is a colourless and odourless gas.
  2. It is the lightest gas and is only sparingly soluble in water.
Q25. Ice is less dense than liquid water
  1. On freezing, water molecules form an open hexagonal arrangement and the volume increases.
  2. So the density of ice is lower than that of water, and it floats.
Q26. Damages buildings and harms aquatic life
  1. It corrodes marble monuments and metal structures.
  2. It acidifies lakes and soil, harming fish and plants.
Section D — Problem Solving (16 marks)
Q27. (a) 17 p, 17 e, 18 n (b) 2, 8, 7 (c) 1
  1. (a) Protons = atomic number = 17; electrons = 17 (neutral atom); neutrons = 35 − 17 = 18.
  2. (b) Configuration: 2, 8, 7.
  3. (c) It needs 1 more electron to complete its octet, so the valency is 1.
Q28. 800 mL
  1. T₁ = 27 + 273 = 300 K; T₂ = 127 + 273 = 400 K.
  2. Charles’ law: V₁/T₁ = V₂/T₂ ⇒ 600/300 = V₂/400.
  3. V₂ = 2 × 400 = 800 mL.
Q29. H ≈ 11.11%, O ≈ 88.89%
  1. Molecular mass of H₂O = 2 + 16 = 18.
  2. % H = (2/18) × 100 = 11.11%.
  3. % O = (16/18) × 100 = 88.89%. Check: 11.11 + 88.89 = 100 ✓.
Q30. (a) Displacement (b) 0.2 g
  1. (a) Zinc displaces hydrogen from the acid, so it is a displacement reaction.
  2. (b) Moles of Zn = 6.5/65 = 0.1.
  3. 1 mol Zn gives 1 mol H₂, so 0.1 mol H₂ = 0.1 × 2 = 0.2 g.
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