Question

Question #85f01

Answer 1

`"1.75 moles"`

Explanation:

The idea here is that we use molarity to show the number of moles of solute present in exactly `"1 L" = 10^3` `"mL"` of a given solution.

In your case, a calcium chloride solution is said to have a molarity of `"3.50 M"`. This tells you that every `"1 L"` of this solution contains exactly `3.50` moles of calcium chloride, the solute.

Since you know that

`"1 L" = 10^3` `"mL"`

you can say that this solution contains `3.50` moles of solute for every `10^3` ``"mL"# of the solution.

Your sample has a volume of

`"500.0 mL" = (10^3color(white)(.)"mL")/color(blue)(2)`

which means that it will contain

`"3.50 moles CaCl"_2/color(blue)(2) = color(darkgreen)(ul(color(black)("1.75 moles CaCl"_2)))`

The answer is rounded to three sig figs, the number of sig figs you have for the molarity of the solution.