Concentration - amount of solute dissolved in a specific amount of solvent concentrated - a lot of solute dilute - very little solute
Percent mass = mass of solute x100 mass of solution Example #1 - In order to maintain a sodium chloride solution similar to ocean water, an aquarium must contain 3.6g of NaCl per 100.0g of water. What is the % mass NaCl of the solution?
Percent mass = mass of solute x100 mass of solution % = 3.6 g x100 103.6g = 3.5% Mass of solute + mass of solvent
Percent (m/v) = mass of solute x100 volume of solution (in mL) Example #2 – How many grams of solute are needed to prepare 2.00L of 2.00% glucose (m/v)
Example #3 - how would you prepare 2.00L of a 5.0M NaCl solution? 5.0 = mol 2.00 L = 10. mol 10. mol NaCl x __________ mol NaCl g 1 58.443
= 580 g NaCl * to make the solution dissolve 584 g of NaCl in enough water to make 2.00 L of solution
Diluting Solutions - using a concentrated solution to make a diluted solution M 1 V 1 = M 2 V 2
Example #4 - what volume, in milliliters, of 2.00 M calcium chloride stock solution would you use to make 0.50 L of 0.300M solution? M1V1 M1V1 = M2V2M2V2 (2.00)(V 1 ) = (.300)(.50) V1 V1 = (0.300)(0.50L) (2.00) V1 V1 = 0.075L = 75 mL