CIE iGCSE Co-Ordinated Science C6.1 Physical and chemical changes Exam Style Questions Paper 1
Question
Which row correctly identifies the named changes?
| physical changes | chemical changes | |
|---|---|---|
| A | condensation and combustion | evaporation and neutralisation |
| B | evaporation and neutralisation | condensation and combustion |
| C | condensation and evaporation | combustion and neutralisation |
| D | combustion and neutralisation | condensation and evaporation |
▶️Answer/Explanation
Answer: C) condensation and evaporation | combustion and neutralisation
Explanation: Condensation and evaporation are physical changes, while combustion and neutralisation are chemical changes.
Question
Which row identifies physical changes and chemical changes?
A cooking an egg and ice melting / rusting of iron
B ice melting and water boiling / burning wood
C mixing sand and water / baking a cake and water boiling
D rusting of iron and baking a cake / solid dissolving and ethanol evaporating
▶Answer/Explanation
Answer: B
Explanation: Physical changes involve changes in state or form without altering the chemical composition (e.g., ice melting, water boiling). Chemical changes involve the formation of new substances (e.g., burning wood).
Question
Some physical and chemical changes are listed.
1 burning methane
2 dissolving sugar in water
3 evaporating ethanol
4 rusting iron
Which changes are chemical changes?
A 1 and 2 B 1 and 4 C 2 and 3 D 3 and 4
▶️Answer/Explanation
Ans :A
Question
Three different processes are listed.
1 heating ice to form water
2 lighting a match
3 removing zinc from sodium chloride solution by filtration
Which processes are physical changes?
A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only
▶️Answer/Explanation
Ans : C
Question
Which change is a chemical change?
(A) combustion of hydrocarbons
(B) filling a balloon with air
(C) freezing a glass of water
(D) mixing salt and sand
▶Answer/Explanation
Ans : A
Question
Which type of reaction is used to manufacture lime from limestone?
(A) addition polymerisation
(B) cracking
(C) neutralisation
(D) thermal decomposition
▶️Answer/Explanation
Ans: D
Question
Four different substances are added to the same acid of the same concentration in reactions W, X, Y and Z.
The initial temperature of the acid before each reaction is 21 ºC.
The final temperatures of the mixtures are measured.
The results are shown.
Which row is correct?
▶️Answer/Explanation
Ans: B
Question
Which processes are chemical changes?
1. conversion of steam to liquid water
2. cracking of alkanes
3. fractional distillation of petroleum
4. thermal decomposition of calcium carbonate
A. 1 and 3
B. 1 and 4
C. 2 and 3
D. 2 and 4
▶️Answer/Explanation
Answer: D. 2 and 4
Explanation: Chemical changes involve the formation of new substances. Cracking of alkanes and thermal decomposition of calcium carbonate both result in the formation of new substances, making them chemical changes. The conversion of steam to liquid water is a physical change, and fractional distillation is a physical separation process.
Question
Which processes are chemical changes?
1. conversion of steam to liquid water
2. cracking of alkanes
3. fractional distillation of petroleum
4. thermal decomposition of calcium carbonate
A. 1 and 3
B. 1 and 4
C. 2 and 3
D. 2 and 4
▶️Answer/Explanation
Answer: D. 2 and 4
Explanation: Chemical changes involve the formation of new substances. Cracking of alkanes and thermal decomposition of calcium carbonate are chemical changes because new substances are formed. The conversion of steam to liquid water and fractional distillation of petroleum are physical changes.