Question #85f01

1 Answer
Nov 5, 2017

Answer:

#"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.