The furring of kettles is caused by the presence in the water of
A. calcium tetraoxosulphate (IV) B. calcium hydrogentrionocarbonate (IV) C. calcium hydroxide D. calcium trioxocarbonate (IV)
Correct Answer: D
Explanation
Calcium hydrogen carbonate, often present in temporary hard water, is boiled in a kettle to remove the hardness. In the process, a scale forms on the inside of the kettle in a process known as furring of kettles. This scale is composed of calcium carbonate.