CHEM 120 Week 3 Assignment; Stoichiometry and Solution Chemisrty

1. Balance these chemical reactions: (2 point each, 8 points total) 2. Calculate the formula mass of Al2(SO4)3. (2 points) 3. Calculate the mass of 2.5 moles of NaOH. (1 points) 4. For the balanced chemical equation: Answer the following questions: a. If you produce 7 mols of KBr, how many mols of MgBr2 did you need? (1 point) b. If I have 2 moles of MgBr2, how much KBr can I make in moles? (2 points) 5. You are making 100 ml of a 2 M solution of HCl. How many ml of a 4 M HCl solution will you require? (2 points) 6. Calculate Volume/volume% of a solution made by dissolving 50 ml Ethanol in 250 ml H2O. (1 point) 7. A solution with a total volume of 2.5 liters is composed of 31.4 grams of Na2S in water. What is the: a. molarity of this solution? (1 point) b. Osmolarity of the solution (1 point) c. the % Mass/Volume of this solution? (1 point)