ICSE Class 10 Chemistry · Exam Practice

Chemistry Practice Paper — Set 1

Chemistry Practice Paper — Set 1. ICSE Class 10 Chemistry, covering the periodic table, chemical bonding, acids and bases, the mole concept, electrolysis, metallurgy, ammonia, hydrogen chloride, nitric and sulphuric acid and organic chemistry, 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 10 Chemistry chapters on MuskMeadow: the periodic table, chemical bonding, acids and bases, the mole concept, electrolysis, metallurgy, ammonia, hydrogen chloride, nitric and sulphuric acid and organic chemistry.
  • 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 pH of pure water at 25°C is

A. 0B. 7C. 10D. 14

2. Ammonia gas is dried using

A. conc. H₂SO₄B. quicklime (CaO)C. P₂O₅D. anhydrous CaCl₂

3. Brown fumes are seen when conc. nitric acid is

A. cooledB. exposed to light or heatedC. dilutedD. neutralised

4. The fountain experiment shows that hydrogen chloride gas is

A. insoluble in waterB. highly soluble in waterC. lighter than airD. a base

5. The property of conc. sulphuric acid used to char sugar is its

A. oxidising natureB. dehydrating natureC. acidic natureD. volatility

6. During the electrolysis of molten lead bromide, lead is deposited at the

A. anodeB. cathodeC. both electrodesD. neither electrode

7. The number of moles in 20 g of NaOH (Na = 23, O = 16, H = 1) is

A. 0.5B. 1C. 2D. 20

8. The chief ore of aluminium is

A. haematiteB. bauxiteC. galenaD. cinnabar

9. The general formula of alkanes is

A. CₙH₂ₙB. CₙH₂ₙ₊₂C. CₙH₂ₙ₋₂D. CₙHₙ

10. Across a period (left to right) the ionisation energy generally

A. decreasesB. increasesC. stays the sameD. becomes zero
8 MARKS

Section B — Fill in the Blanks & True / False

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

11. Avogadro’s number is ______.

12. The catalyst used in the Haber process is ______.

13. Anions are attracted to the anode during electrolysis. (   )

14. Covalent compounds conduct electricity in the molten state. (   )

15. The catalyst used in the Contact process is ______.

16. The functional group of alcohols is ______.

17. Electronegativity decreases down a group. (   )

18. The volume of 1 mole of any gas at STP is ______ litres.

16 MARKS

Section C — Short Answer Questions

Show your working. (2 marks each)

19. Calculate the relative molecular mass of ammonia (N = 14, H = 1).

20. Write the equation for the reaction of ammonia with hydrogen chloride.

21. What is the volume of 2 moles of a gas at STP?

22. Name the alloy of copper and zinc.

23. Write the IUPAC name of CH₃CH₂OH.

24. Find the mass of 0.25 mole of CO₂ (C = 12, O = 16).

25. Why does conc. nitric acid turn yellow on standing?

26. Name the gases formed at the cathode and the anode in the electrolysis of acidified water.

16 MARKS

Section D — Problem Solving

Show all steps. (4 marks each)

27. 4.4 g of carbon dioxide (C = 12, O = 16) is taken. Find (a) the number of moles, (b) the number of molecules and (c) the volume at STP. (Avogadro’s number = 6.022 × 10²³)

28. For the reaction N₂ + 3H₂ → 2NH₃, find (a) the mass of ammonia formed from 28 g of nitrogen and (b) the volume of hydrogen needed at STP. (N = 14, H = 1)

29. A compound contains 40% carbon, 6.7% hydrogen and 53.3% oxygen. Find its empirical formula and, if the relative molecular mass is 60, its molecular formula. (C = 12, H = 1, O = 16)

30. Describe how an iron spoon is electroplated with silver. Name the anode, cathode and electrolyte and write the reaction at each electrode.

ICSE Class 10 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. 7

Pure water is neutral with pH 7 at 25°C.

Q2. B. quicklime (CaO)

Ammonia reacts with acidic drying agents and with CaCl₂, so basic quicklime is used.

Q3. B. exposed to light or heated

4HNO₃ → 4NO₂ + 2H₂O + O₂; the brown gas is nitrogen dioxide.

Q4. B. highly soluble in water

HCl dissolves rapidly in water, lowering the pressure in the flask and drawing water up as a fountain.

Q5. B. dehydrating nature

It removes the elements of water from sugar, leaving carbon.

Q6. B. cathode

Pb²⁺ gains electrons at the cathode: Pb²⁺ + 2e⁻ → Pb.

Q7. A. 0.5

Molar mass of NaOH = 40 g/mol, so moles = 20/40 = 0.5.

Q8. B. bauxite

Bauxite (Al₂O₃·2H₂O) is the chief ore of aluminium.

Q9. B. CₙH₂ₙ₊₂

Alkanes are saturated: CₙH₂ₙ₊₂, e.g. CH₄, C₂H₆.

Q10. B. increases

Nuclear charge increases while atomic size decreases, so electrons are held more tightly.

Section B — Fill in the Blanks & True / False (8 marks)
Q11. 6.022 × 10²³

It is the number of particles in one mole.

Q12. iron

Finely divided iron with promoters is used: N₂ + 3H₂ ⇌ 2NH₃.

Q13. True

Anions are negative, so they move to the positive electrode (anode).

Q14. False

They have no free ions or mobile electrons, so they do not conduct.

Q15. vanadium pentoxide (V₂O₅)

SO₂ is oxidised to SO₃ over V₂O₅ at about 450°C.

Q16. –OH (hydroxyl)

Examples: methanol CH₃OH, ethanol C₂H₅OH.

Q17. True

The larger atoms attract the bonding pair less strongly.

Q18. 22.4

This is the molar volume at 0°C and 1 atm.

Section C — Short Answer Questions (16 marks)
Q19. 17
  1. NH₃ has 1 N and 3 H atoms.
  2. 14 + 3 × 1 = 17.
Q20. NH₃ + HCl → NH₄Cl
  1. The two gases combine to form white fumes of ammonium chloride.
  2. NH₃ + HCl → NH₄Cl.
Q21. 44.8 litres
  1. Volume = moles × 22.4 L.
  2. 2 × 22.4 = 44.8 L.
Q22. Brass
  1. Brass contains copper and zinc (and is harder than copper).
  2. Bronze, in contrast, is copper and tin.
Q23. Ethanol
  1. The carbon chain has 2 carbons: eth-.
  2. It contains the –OH group, so the suffix is -ol: ethanol.
Q24. 11 g
  1. Molar mass of CO₂ = 12 + 32 = 44 g/mol.
  2. Mass = 0.25 × 44 = 11 g.
Q25. Dissolved NO₂
  1. In light it decomposes slightly to NO₂.
  2. The brown NO₂ dissolves in the acid and gives it a yellow colour.
Q26. Hydrogen at cathode, oxygen at anode
  1. At the cathode H⁺ ions gain electrons to form hydrogen.
  2. At the anode hydroxide ions lose electrons to give oxygen; the volumes are in the ratio 2 : 1.
Section D — Problem Solving (16 marks)
Q27. (a) 0.1 mol (b) 6.022 × 10²² molecules (c) 2.24 L
  1. (a) Molar mass = 44 g/mol, so moles = 4.4/44 = 0.1.
  2. (b) Molecules = 0.1 × 6.022 × 10²³ = 6.022 × 10²².
  3. (c) Volume = 0.1 × 22.4 = 2.24 L.
Q28. (a) 34 g (b) 67.2 L
  1. Moles of N₂ = 28/28 = 1.
  2. (a) 1 mol N₂ gives 2 mol NH₃ = 2 × 17 = 34 g.
  3. (b) 1 mol N₂ needs 3 mol H₂ = 3 × 22.4 = 67.2 L at STP.
Q29. Empirical CH₂O; molecular C₂H₄O₂
  1. Moles: C = 40/12 = 3.33, H = 6.7/1 = 6.7, O = 53.3/16 = 3.33.
  2. Divide by the smallest (3.33): C : H : O = 1 : 2 : 1, so the empirical formula is CH₂O (mass 30).
  3. n = 60/30 = 2, so the molecular formula is C₂H₄O₂.
Q30. Anode: silver; cathode: spoon; electrolyte: silver salt solution
  1. Anode: pure silver rod; cathode: the iron spoon; electrolyte: a solution of a silver salt such as sodium argentocyanide (or silver nitrate).
  2. At the anode: Ag → Ag⁺ + e⁻.
  3. At the cathode: Ag⁺ + e⁻ → Ag, forming a thin layer on the spoon.
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