CIE iGCSE Co-Ordinated Science C1.1 Solids, liquids and gases Exam Style Questions Paper 1
Question
In which substance are the particles closest together at room temperature?
(A) CO$_{2}$
(B) Ne
(C) N$_{2}$
(D) Zn
▶️Answer/Explanation
Ans: D
Question
Which properties are used to distinguish between solids and gases?
1 compressibility
2 melting point
3 flammability
(A) 1 and 2 only
(B) 1 and 3 only
(C) 2 and 3 only
(D) 1, 2 and 3
▶️Answer/Explanation
Ans : A
Question
Cyclopentane is a hydrocarbon.
The melting point of cyclopentane is –94 °C and its boiling point is 49 °C.
In process 1, the temperature of cyclopentane changes from 55 °C to 45 °C.
In process 2, the temperature of cyclopentane changes from –100 °C to –90 °C.
Which row identifies the changes in processes 1 and 2?
▶️Answer/Explanation
Ans: D
Solution:
To determine the correct row, we need to analyze the temperature changes in processes 1 and 2:
- Process 1: Temperature changes from 55 °C to 45 °C.
- At 55 °C, cyclopentane is a gas (above its boiling point of 49 °C).
- At 45 °C, cyclopentane is a liquid (below its boiling point but above its melting point of –94 °C).
- This change represents condensation (gas to liquid).
- Process 2: Temperature changes from –100 °C to –90 °C.
- At –100 °C, cyclopentane is a solid (below its melting point of –94 °C).
- At –90 °C, cyclopentane is a liquid (above its melting point but below its boiling point).
- This change represents melting (solid to liquid).
Correct Answer:
(D) condensation and melting
- Process 1: Condensation (gas to liquid).
- Process 2: Melting (solid to liquid).
Question
Blue cobalt(II) chloride paper is added to a liquid. It changes from blue to pink.
What is the liquid?
A) bromine
B) ethanol
C) petrol
D) water
▶️Answer/Explanation
Answer: D) water
Explanation: Cobalt(II) chloride paper turns from blue to pink in the presence of water, indicating that the liquid is water.