How many grams of CaCl2 would be required to be added to water to prepare 1 Liter (1000ml) of a 1.72% (w/v) aqueous solution of CaCl2?

Answer 1

1.72% w/v means 1.72 g/100 mL soln.
So if 1.72 grams are needed for 100 mL, then 17.2 g would be needed to prepare 1000 mL.