Chem 112 quiz 2008

Chemistry 112 Quiz 3A Tuesday Feb. 5, 2008 Name: Section: 1. The chemical structures of both hexane and ribose contain carbon atoms. CH₃CH₂CH₂CH₂CH₂CH₃ OH hexane H-C-H 0 OH ribose HH a) Is hexane soluble in water? No Give the reason for your answer. Hexane is a nonpolar molecule. Nonpolar solutes (substances/molecules) dissolve in nonpolar solvents. Since water is a polar solvent hexane will not dissolve in water. Like dissolves like. b) Is ribose soluble in water? Yes Give the reason for your answer. Ribose is polar, water is polar. Like dissolves like. 2. The solubility of LiCl is 80 g/100 g of H₂O, at 24°C. Suppose that you add 170 g of LiCl to 200 g of H₂O, at 24°C: a) How much of the 170 g of LiCl will dissolve in 200 g of H₂O, at 24°C. (Show your work.) 200g H₂O * (80g LiCl / 100g H₂O) = 160g LiCl or 160g LiCl dissolves in 200g H₂O b) How much of the 170 g of LiCl will not dissolve in 200 g of H₂O, at 24°C. (show your work) 170g LiCl - 160g LiCl = 10g LiCl Of the 170g LiCl added, 10g LiCl that will not dissolve.