A solution is prepared by dissolving 27.7 g of CaCl2 in 375 g of water. The density of the resulting solution is 1.05 g/mL. The concentration of CaCl2 is ________% by mass. A solution is prepared by dissolving 27.7 g of CaCl2 in 375 g of water. The density of the resulting solution is 1.05 g/mL. The concentration of CaCl2 is ________% by mass. 6.24 6.88 7.22 0.0722 0.0688