The grams of cacl2 are presented in 25 ml of a 0.500 M solution is calculated as follows
find the number of moles
moles= molarity x volume/1000
= 0.500 x25 /1000 =0.0125 moles
mass = moles x molar mass of cacl2
= 0.0125 mol x 111.1 g/mol =1.389 grams