1. cuso4 h20 containing 3.5 percent of a soluble impurity is dissolved continuously in sufficient water and recycled mother liquor to make a saturated solution at 80 degc, the solution is then cooled to 25degc and crystals of cuso4 5h20 thereby obtained. these crystals carry 10 percent of their dry weight as adhering mother liquor. the crystals are the dried to zero free water (cuso4 5h20). the allowable impurity in the product is 0.6 percent. calculate (1) the weight of water and the recycled mother liquor required per 100 kg of impure copper sulfate; (b) the percentage recovery of copper sulfate, assuming that the mother liquor not recycled is discarded. the solubility of cuso4 5h20 at 80 deac is 120 g per 100 g of free h20 and at 25degc is 40 degc per 100 g of free h20. 2. a solution of mgso4 containing 43 g of solid per 100 g of water is fed to a vacuum crystallizer at 220degf. the vacuum, in the crystallizer corresponds to an h20 boiling temperature at 43degf, and a saturated solution of mgso4 has a boiling point elevation of 2degf. how much solution must be fed to the crystallizer to produce 900 kg of epson salt (mgso4 7h20) per hour.