Physical and Chemical Change Exam Questions
Practice IGCSE Chemistry exam questions on physical and chemical change. Covers distinguishing between physical and chemical changes, evidence for chemical reactions, and writing word and symbol equations with mark schemes and examiner notes.
Published by IGCSEChemistry.com.my
Chemistry teaching team: K. S. Tan (15+ years teaching IGCSE Chemistry) and Ms Yash (10+ years teaching IGCSE Chemistry) and Ms Kartini (15+ years teaching IGCSE Chemistry).
Mapped to Cambridge IGCSE Chemistry 0620 (2026–2028). Last updated 2026-08-19.
These questions cover physical and chemical change. Write full answers before checking.
Question 1 (2 marks, Core)
State two differences between a physical change and a chemical change.
Mark scheme
Any two from:
- A physical change is easily reversed; a chemical change is difficult to reverse / usually irreversible [1]
- No new substance is formed in a physical change; a new substance is formed in a chemical change [1]
- Little or no energy change in a physical change; a chemical change usually involves a significant energy change [1]
Examiner note: “Physical changes can be undone” is too vague. State “easily reversed” or “reversible.” For chemical changes, the key point is that new substances with different properties are formed.
Question 2 (3 marks, Core)
Classify each of the following as a physical change or a chemical change:
(a) Dissolving sugar in water (1)
(b) Burning magnesium ribbon (1)
(c) Melting ice (1)
Mark scheme
(a) Physical change [1]
(b) Chemical change [1]
(c) Physical change [1]
Examiner note: Dissolving sugar is physical because no new substance is formed — the sugar can be recovered by evaporation. Burning magnesium is chemical because a new substance (magnesium oxide) is formed. Melting ice is a change of state — physical.
Question 3 (3 marks, Core)
A student adds dilute hydrochloric acid to sodium carbonate powder. Bubbles are produced, the mixture gets slightly warm, and a clear solution remains.
(a) State three pieces of evidence that a chemical reaction has occurred. (3)
Mark scheme
- Gas/bubbles produced [1]
- Temperature change / gets warm (exothermic) [1]
- The solid dissolves / disappears forming a new solution [1]
Examiner note: “Something happened” is not evidence. Each piece of evidence must be a specific observable change. Gas production, temperature change, colour change, precipitate formation, and light/sound production are all valid types of evidence.
Question 4 (4 marks, Core)
Name the type of chemical reaction occurring in each example:
(a) Zinc + copper sulfate solution → zinc sulfate + copper (1)
(b) Calcium carbonate → calcium oxide + carbon dioxide (when heated) (1)
(c) Hydrochloric acid + sodium hydroxide → sodium chloride + water (1)
(d) Methane + oxygen → carbon dioxide + water (1)
Mark scheme
(a) Displacement [1]
(b) Thermal decomposition [1]
(c) Neutralisation [1]
(d) Combustion [1]
Examiner note: Learn to recognise reaction types from patterns: displacement = more reactive element replaces less reactive one; decomposition = one substance breaks into two or more; neutralisation = acid + base → salt + water; combustion = substance + oxygen → oxides + energy.
Question 5 (3 marks, Core)
When a piece of iron is left outside in wet conditions, it gradually turns into a reddish-brown substance.
(a) Name this process. (1)
(b) Is this a physical or chemical change? Explain your answer. (2)
Mark scheme
(a) Rusting / corrosion [1]
(b) It is a chemical change [1] because a new substance (iron oxide / rust) is formed with different properties, and the change is not easily reversed [1]
Examiner note: Rusting produces hydrated iron(III) oxide, which has different properties from iron. The change is not reversible by simple physical methods — the iron must be chemically reduced to recover it.
Question 6 (2 marks, Supplement)
Explain why dissolving sodium chloride in water is considered a physical change, even though the solid appears to “disappear.”
Mark scheme
- No new substance is formed — the sodium chloride is still present as Na+ and Cl- ions in solution [1]
- The process is easily reversed by evaporating the water to recover the solid sodium chloride [1]
Examiner note: The ions separate but are not changed into different substances. The NaCl can be fully recovered. Contrast this with dissolving a metal in acid, which IS a chemical change because new substances are formed.
Question 7 (4 marks, Supplement)
A student heats copper(II) sulfate pentahydrate crystals (CuSO4.5H2O). The blue crystals turn to a white powder and steam is given off.
(a) Write a word equation for this reaction. (1)
(b) Is this a physical or chemical change? Justify your answer. (2)
(c) How could the student prove the change is reversible? (1)
Mark scheme
(a) Hydrated copper sulfate → anhydrous copper sulfate + water [1]
(b) This is debatable, but at IGCSE level it is treated as a chemical change [1] because a new substance (anhydrous copper sulfate) with different properties (white instead of blue) is formed [1]
(c) Add water to the white powder — it will turn blue again and get hot, showing the change is reversed [1]
Examiner note: This is an unusual example because the change IS easily reversible (adding water restores the blue colour), yet it involves breaking chemical bonds (the water of crystallisation is bonded to the CuSO4). Examiners typically accept “chemical change” for this. The reversibility test (adding water) is a standard practical.
What to revise if you scored below 5
If you confused physical and chemical changes, memorise the key distinction: chemical changes form new substances. If reaction type identification was difficult (Question 4), learn the five main types: combustion, neutralisation, displacement, decomposition, and oxidation. Revisit the physical and chemical change notes.
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