Solution: A mixture of 100 g of K 2Cr2O7 and 200 g of water is stirred at 60°C until no more of the salt dissolves. The resulting solution is poured off, leaving the undissolved solid behind. The solution is now cooled to 20°C. What mass of K2Cr2O7 crystallizes from the solution during the cooling? a) 24 g b) 31 g c) 43 g d) 62 g