The scale formation in a kinetic 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
Correct Answer: Option C
Explanation
The scale is produced when soluble Ca(HCO3)2 breaks down on heating to form insoluble CaCO3
eqn Ca (HCO3)2(aq) —> CaCO3 (s) + CO2 (g) + H2O (l)