Solution Concentration Section 14.2

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 x g = 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)

2.00% = g x mL = 40.0 g

Molarity (M) = moles solute liters of solution Example #3 - A mL intravenous solution contains 5.10g of glucose (C 6 H 12 O 6 ). What is the molarity of this solution?

Molarity (M) = moles solute liters of solution 5.10g C 6 H 12 O 6 x __________ g C 6 H 12 O 6 mol C 6 H 12 O = mol mL =.1005 L

M = mol L = mol/L or M

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

= 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