# Question 32650

Oct 28, 2017

$\text{55.5 g}$

#### Explanation:

Start by calculating the number of moles of calcium chloride that must be dissolved in your solution in order for it to have a molarity of ${\text{0.100 mol L}}^{- 1}$.

You know that this solution must contain $0.100$ moles of calcium chloride for every $\text{1 L}$ of the solution, so you can say that your sample must contain

5.00 color(red)(cancel(color(black)("L solution"))) * "0.100 moles CaCl"_2/(1color(red)(cancel(color(black)("L solution")))) = "0.500 moles CaCl"_2#

Now, to convert the number of moles of calcium chloride to moles, you need to use the molar mass of the salt.

$0.500 \textcolor{red}{\cancel{\textcolor{b l a c k}{\text{moles CaCl"_2))) * "110.98 g"/(1color(red)(cancel(color(black)("mole CaCl"_2)))) = color(darkgreen)(ul(color(black)("55.5 g}}}}$

The answer is rounded to three sig figs.