Chapter 15, Problem 109E

One of the main components of hard water is ${\text{CaCO}}_{\text{3}}$. When hard water evaporates, some of the ${\text{CaCO}}_{\text{3}}$ is left behind as a white mineral deposit. Plumbing fixtures in homes with hard water often acquire these deposits over time. Toilets, for example, may develop deposit at the water line as the water in the toilet slowly evaporates away. If water is saturated with ${\text{CaCO}}_{\text{3}}$, how much of it has to evaporate to deposit 0.250 g of ${\text{CaCO}}_{\text{3}}$

? Hint: Begin by using $K_{\text{sp}}$ for ${\text{CaCO}}_{\text{3}}$ to determine its solubility.