Unit 10B Review Reg Chem 2012-13 11 • When a solution sits out over a long period of time and water evaporates the concentration of the solution __________. Increases. As the volume of solution decreases, the molarity (concentration) increases 12 • List an example of a solution that would naturally dilute. Ice in pop 13 • What does solution concentration describe? Molarity: amount of solute dissolved in a given amount of solvent 14 • What do we use to describe solution concentration in chemistry? Molarity 15 • If a solution is “strong” it is concentrated • If a solution is “weak” it is dilute 16 • What does it mean to dilute a solution? What equation do we use for dilutions? To lower its concentration “water it down” Yet keep the number of moles the same M1V1 = M2V2 17 • What is the molarity of a sodium chloride solution that contains 1.73 moles in 3.94 L of solution? mol 1.73mol M 0.439 M L 3.94 L 18 • What is the molarity of sodium hydroxide solution that contains 23.5 g NaOH in 500.0 mL of solution? 1mol 0.588mol 23.5 gNaOHx 1.18M 40.00 g 0.5000 L 19 • How many grams of potassium nitrate are in 275 mL of 1.25 M solution? x 1.25M 0.344mol 0.275L KNO3 101.11g x 34.8 g 1mol KNO3 20 • How many mL of 3.25 M hydrochloric acid would contain 16.0 grams of solute? 1mol 16.0 gHClx 0.439mol 36.46 g 3.25M 0.439mol 135mL x 21 • You have 12.0 M HCl in your stock room, how would you prepare 600.0 mL of 2.50 M HCl solution? (12.0 M)(x) = (2.50 M)(600.0 mL) X=125 mL Measure out 125 mL of stock solution. Add 475 mL of distilled water. 22 • How would you correctly prepare 500.0 mL of a 3.0 M solution of NaOH from solid solute? x 3.0M 1.5mol 0.5000 L NaOH Measure out 60 g of NaOH (s) Add water to the 500.0 mL line 40.00 g x 60 g 1mol 23 • How would you prepare 500 mL of 3.0 M NaOH from 12.0 M concentrated stock solution? (12.0 M)(X) = (3.0 M)(500 mL) X=125 mL Measure out 125 mL of stock solution. Add it to 375 mL of distilled water 26 • An excess of zinc is added to 125 mL of 0.100 M HCl solution. What mass of zinc chloride is formed? Zn + 2HCl ZnCl2 + H2 x 0.100M 0.125L