CIE iGCSE Co-Ordinated Science C10.1 Water Exam Style Questions Paper 1
Question
Other than hydrogen and oxygen, which substance provides only one of the essential elements for plant growth?
A. K₃PO₄
B. KNO₃
C. (NH₄)₃PO₄
D. NH₄NO₃
▶️Answer/Explanation
Answer: D
Explanation: NH₄NO₃ (ammonium nitrate) provides only nitrogen, which is one of the essential elements for plant growth. The other substances provide multiple elements.
Question
In order to make water from reservoirs fit to drink, ……1…… is used to kill bacteria. Water in a condenser is used during distillation as a ……2…… . When water is used to make ethanol from ethene, it is acting as a ……3…… . Which words correctly complete gaps 1, 2, and 3?
A. Chlorination, coolant, reactant
B. Chlorination, solvent, solvent
C. Filtration, coolant, reactant
D. Filtration, solvent, solvent
▶️Answer/Explanation
Answer: A
Explanation: Chlorination is used to kill bacteria in water. In distillation, water acts as a coolant in the condenser. When making ethanol from ethene, water acts as a reactant.
Question
What is a chemical test for water?
A. It turns anhydrous cobalt(II) chloride white.
B. It turns anhydrous copper(II) sulfate blue.
C. It turns blue copper(II) sulfate white.
D. It turns pink cobalt(II) chloride blue.
▶️Answer/Explanation
Answer: B. It turns anhydrous copper(II) sulfate blue.
Explanation: Anhydrous copper(II) sulfate (white) turns blue in the presence of water, making it a reliable chemical test for water.
Question
Which colour is observed when water is added to anhydrous copper(II) sulfate?
A) blue
B) green
C) pink
D) white
▶️Answer/Explanation
Answer: A) blue
Explanation: Anhydrous copper(II) sulfate is white, but it turns blue when water is added, forming hydrated copper(II) sulfate.