Question 47
WaterThe scale formation in a kettle used for boiling water is caused by the presence in water of
- A.calcium sulphate
- B.calcium carbonate
- C.calcium hydrogen carbonate
- D.calcium hydroxide
- E.magnesium sulphate
Show the answer and explanation
Answer: C (calcium hydrogen carbonate)
Explanation
Dissolved calcium hydrogen carbonate decomposes on boiling to insoluble calcium carbonate, which forms the scale (fur) in kettles.