how many grams of CaCl2 are needed to make 597.9 g of a solution that is 31.0% (m/m) calcium chloride in water?

Question

note that mass is not technically the same thing as weight, but % (m/m) has the same meaning as % (w/w). how many grams of water are needed to make this solution?

Answer 1

Hello again, Nicole.

 

31% (m/m) means there are 31 g CaCl2/100 g solution

If you have 597.9 g of solution, how many grams of CaCl2 would there be in a 31% (m/m) solution?

31 g CaCl2/100 g solution x 597.9 g solution = 185.3 g CaCl2

 

Since you have 185.3 g CaCl2, and the total mass of solution is 597.9 g, the mass of water must be 597.9 g - 185.3 g or mass of water = 412.6 g