CIE iGCSE Co-Ordinated Science C10.2 Air quality and climate Exam Style Questions Paper 1
Question
Which statements about limestone are correct?
1. Limestone is used to neutralise industrial waste products.
2. Limestone is used to treat acidic soil.
3. Thermal decomposition of limestone produces calcium oxide.
A. 1 and 2 only
B. 1 and 3 only
C. 2 and 3 only
D. 1, 2 and 3
▶️Answer/Explanation
Answer: D. 1, 2 and 3
Explanation: Limestone (calcium carbonate) is used to neutralize acidic waste and soil. When heated, it undergoes thermal decomposition to produce calcium oxide (quicklime) and carbon dioxide.
Question
Which process does not produce carbon dioxide?
A complete combustion of fossil fuels
B reaction of an acid with a carbonate
C respiration in plants
D rusting iron
▶️Answer/Explanation
Answer: D rusting iron
Explanation: Rusting iron involves the reaction of iron with oxygen and water to form iron oxide, but it does not produce carbon dioxide. The other processes listed all produce carbon dioxide as a byproduct.
Question
Why do farmers add limestone to soil?
A It acts as a fertiliser.
B It adds nitrogen to the soil.
C It decreases the pH of the soil.
D It increases the pH of the soil.
▶️Answer/Explanation
Ans : D
Question
What is not a use of limestone?
(A) manufacture of calcium oxide
(B) neutralising industrial waste products
(C) purifying water
(D) treating acidic soil
▶️Answer/Explanation
Ans: C