Question

Question #c814d

Answer 1

`"3.5% m/v"`

Explanation:

I'm assuming that the problem wants you to find the mass by volume percent concentration, `"% 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, `"CaCl"_2`, are present in `"100 mL"` of solution.

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

In your case, you know that `"250 mL"` of this solution contain `"8.56 g"` of calcium chloride, which means that `"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 `"100 mL"` of solute, you can say that the solution's `"%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