Physical & Chemical States — Homi Bhabha Class 9 Chemistry MCQs with Solutions
Free Homi Bhabha Class 9 Chemistry Physical & Chemical States MCQs with step-by-step solutions (9 questions). Part of Matter & Its States. Practise online on Prepizo — no login needed.
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Questions with solutions
Q1 — Physical & Chemical States · medium · theory
A change in which no new substance is formed and which is usually reversible is a:
A. chemical change
B. nuclear change
C. combustion
D. physical change ✓ Correct
Solution: Physical changes (e.g. melting, dissolving) form no new substance and are often reversible.
Q2 — Physical & Chemical States · medium · theory
The rusting of iron is an example of a:
A. physical change
B. reversible change
C. chemical change ✓ Correct
D. change of state only
Solution: Rusting forms a new substance (iron oxide), so it is a chemical change.
Q3 — Physical & Chemical States · hard · theory
Which of the following is a chemical change?
A. Burning of paper ✓ Correct
B. Breaking a glass
C. Dissolving salt in water
D. Melting of wax
Solution: Burning produces new substances (ash, gases) and is a chemical change; the others are physical.
Q4 — Physical & Chemical States · medium · theory
Melting of ice into water is a physical change because:
A. no new substance is formed and it can be reversed by freezing ✓ Correct
B. a new substance (water) is created
C. it is irreversible
D. it releases a gas
Solution: Ice and water are the same substance in different states; freezing reverses the change.
Q5 — Physical & Chemical States · hard · theory
Which set contains ONLY chemical changes?
A. Freezing water, evaporating water, crushing a can
B. Tearing paper, breaking chalk, melting wax
C. Melting of ice, boiling of water, dissolving sugar
D. Burning of coal, souring of milk, rusting of iron ✓ Correct
Solution: Burning, souring and rusting all form new substances (chemical changes); the others are physical.
Q6 — Physical & Chemical States · medium · theory
Dissolving common salt in water is considered a physical change because:
A. a new compound is formed
B. the salt can be recovered by evaporation ✓ Correct
C. a gas is released
D. the change is irreversible
Solution: No new substance forms; evaporating the water recovers the original salt, so it is physical.
Q7 — Physical & Chemical States · medium · theory
Which set contains ONLY physical changes?
A. Burning of a candle, cooking of food, digestion of bread
B. Photosynthesis, respiration, fermentation of sugar
C. Boiling of water, magnetising an iron bar, chopping of wood ✓ Correct
D. Souring of milk, rusting of a nail, ripening of fruit
Solution: Boiling, magnetising and chopping form no new substance and are reversible or easily undone, so all three are physical changes. Each of the other sets involves new substances being formed.
Q8 — Physical & Chemical States · medium · theory
When a candle burns, the solid wax first melts and then the wax vapour burns with a flame. Which statement is correct?
A. Both melting and burning of the wax are chemical changes
B. Melting of the wax is a physical change and burning is a chemical change ✓ Correct
C. Melting is a chemical change and burning is a physical change
D. Both melting and burning of the wax are physical changes
Solution: Melting only changes the state of the wax (physical), while burning produces new substances such as carbon dioxide and water vapour (chemical), so the two steps are different in nature.
Q9 — Physical & Chemical States · hard · theory
A student lists four features of a chemical change: (i) a new substance is formed, (ii) it is usually difficult to reverse, (iii) energy is often absorbed or released, (iv) only the state of matter changes. Which listed feature is WRONG for a chemical change?
A. Feature (iv) ✓ Correct
B. Feature (ii)
C. Feature (i)
D. Feature (iii)
Solution: Feature (iv), a change in state only, describes a physical change. In a chemical change a new substance forms, it is usually hard to reverse, and energy is often exchanged.