Question c814d

Apr 6, 2016

$\text{3.5% m/v}$

Explanation:

I'm assuming that the problem wants you to find the mass by volume percent concentration, $\text{% m/v}$, for this calcium chloride solution.

A solution's mass by volume percent concentration tells you how many grams of solute, which in your case is calcium chloride, ${\text{CaCl}}_{2}$, are present in $\text{100 mL}$ of solution.

This means that in order to find a solution's $\text{% m/v}$ concentration, you essentially have to determine how many grams of solute you get in $\text{100 mL}$ of said solution.

In your case, you know that $\text{250 mL}$ of this solution contain $\text{8.56 g}$ of calcium chloride, which means that $\text{100 mL}$ will contain

100 color(red)(cancel(color(black)("mL"))) * "8.56 g CaCl"_2/(250color(red)(cancel(color(black)("mL")))) = "3.46 g CaCl"_2

So, if this is how much solute you get per $\text{100 mL}$ of solute, you can say that the solution's $\text{%m/v}$ concentration is equal to

"% m/v" = color(green)(|bar(ul(color(white)(a/a)"3.5% CaCl"_2color(white)(a/a)|))) -># rounded to two sig figs