Calculate the mass of 8 00 w w NaOH solution that contains 32 0 g of NaOH Mass of solute x 100 Mass of solution 32 0 g x g 08 x 400 g solution 1 Calculate the mass of NaOH in 300 0 mL of an 8 00 w w NaOH solution Density is 1 09 g mL 300 D m v 1 09 g mL m 300 0 L m 327 g NaOh Mass of solute mass of solution x 100 x g 327 g 08 x 26 2 g 2 What volume of 12 0 w w KOH contains 40 0 g of KOH The density of the solution is 1 11 g mL 1 11 g mL 40 0 g v v 36 0 mL in 12 0 36 0 mL 12 0 x 100 x 300 mL 3 Concentrations of Solutions Second common unit of concentration number of moles of solute molarity number of liters of solution moles M L mmol M mL 4 Concentrations of Solutions Calculate the molarity of a solution that contains 12 5 g of sulfuric acid in 1 75 L of solution Molarity moles liter 12 5 g H2SO4 96 065 g mol 127 moles H2SO4 M 127 1 75 0728 M H2SO4 5 Clicker question What is the molarity of a solution that contain 10 0 moles of a solute in 2 00 l of solution M 10 0 moles 2 00 L 5 00 Determine the mass of calcium nitrate required to prepare 3 50 L of a 0 800 M calcium nitrate 800 M x moles 3 50 L x 2 80 moles Ca NO3 2 x 164 1 g mol x 459 g Ca NO3 2 7 Concentrations of Solutions One of the reasons that molarity is commonly used is because M x L moles solute and M x mL mmol solute 8 The specific gravity of a concentrated HCl is 1 185 and it is 36 31 w w HCl What is its molarity Specific gravite density of substance density of water Density 1 185 g ml HCl 36 31 g 100 0g 43027 g mol 43027 g mol 1000 mol L 430 27 g L 36 46 g mol 11 8 moles L HCl 9 Dilution of Solutions To dilute a solution add solvent to a concentrated solution One method to make tea less sweet How fountain drinks are made from syrup The number of moles of solute in the two solutions remains constant The relationship M1V1 M2V2 is appropriate for dilutions but not for chemical reactions 10 Dilution of Solutions Common method to dilute a solution involves the use of volumetric flask pipet and suction bulb 11 If 10 0 mL of 12 0 M HCl is added to enough water to give 100 mL of solution what is the concentration of the solution M1V1 M2V2 12 0 M 0100 L M2 100L M2 1 2 M 12 Clicker question What volume of an 18 0 M sulfuric acid is required to make 2 50 L of a 2 40 M sulfuric acid solution 18 0 M V1 2 40 M 2 50 L V1 333 L 13 Using Solutions in Chemical Reactions Combine the concepts of molarity and stoichiometry to determine the amounts of reactants and products involved in reactions in solution 14 What volume of a 0 500 M BaCl2 is required to completely react with 4 32 g of Na2SO4 Na 2SO 4 BaCl 2 BaSO 4 2 NaCl 4 32 g Na2SO4 142 05 g mol 0304 mol 0304 mol Na2SO4 1 mol BaCl2 1 mol Na2SO4 0304 mol BaCL2 500 M 0304 mol V V 0608 L BaCl2 60 8 mol 500 M BaCl2 15 a What volume of a 0 200 M NaOH will react with 50 0 mL of a 0 200 M aluminum nitrate Al NO3 3 Al NO3 3 3 NaOH Al OH 3 3 NaNO3 50 0 mL 1L 1000 mL 0 050 L 200 M x moles 050 L x 0 010 moles Al NO3 3 01 mol Al NO3 3 3 mol NaOH 1 mol Al NO3 3 0 030 moles NaOH 0300 moles NaOH 200 moles L 0 150 L 150 mL of 200 M NaOH 16 b What mass of Al OH 3 precipitates in a 0 0100 mol Al NO3 3 1 mol Al OH 3 1 mol Al NO3 3 0 0100 mol Al OH 3 0100 mol Al OH 3 77 98 g mol 0 780 g Al OH 3 17 Using Solutions in Chemical Reactions Titrations are a method of determining the concentration of an unknown solutions from the known concentration of a solution and solution reaction stoichiometry Requires special lab glassware Buret pipet and flasks Must have an indicator also 18 What is the molarity of a KOH solution if 38 7 mL of the KOH solution is required to react with 43 2 mL of a 0 223 M HCl KOH HCl KCl H 2O 19 Clicker question of moles 44 1 mL of a 0 103 M HCl What is the molarity of a barium hydroxide solution if 44 1 mL of a 0 103 M HCl is required to react with 38 3 mL of the Ba OH 2 solution Ba OH 2 2 HCl BaCl2 2 H 2O 21