1. Solution Concentration For Today: Concentrations of Solutions Descriptive and Calculated Tonight: Homework sheet Next Time: Problem Solving

2. Yesterday Solution vocabulary Lots of solution vocabulary Lots and lots Today A little more vocabulary Then we start calculations

3. Concentration Concentration is a measure of how much solute is dissolved in a solvent. If there is a lot of solute, we call it concentrated. If there is only a little solute, we call it dilute.

4. More Descriptions Unsaturated is a solution that could hold more solute than it currently is holding Saturated is a solution that contains as much solute as it can. Supersaturated is a solution that is holding more than it should be able to under the given conditions.

5. When Adjectives Aren’t Good Enough It’s nice to be able to say that something is concentrated or dilute. Some things need more description. Important things like medicines or oxygen in the air.

6. Concentration #1: Mass Percent Mass Percent is the mass of solute in a given mass of solution Formula mass percent = mass solute x 100 mass solution

7. Mass Percent: Example What is the mass percent of sugar in a typical can of cola? A cola has a mass of about 355g and of that, about 36g is sugar. mass percent = mass solute x 100 mass solution mass percent = 36g sugar x100 355g total solution mass percent = 10.14% sugar in cola

8. Mass Percent: You Try What is the mass percent of sweetener in a typical can of diet cola? A diet cola has a mass of about 335g and of that, about 0.2g is the sweetener. mass percent = mass solute x 100 mass solution mass percent = 0.2g sweetener x100 335g total solution mass percent = 0.060% sweetener in diet cola

9. Concentration #2: Molarity Molarity is the amount of solute in moles divided by the volume of solution in liters. It is the most commonly used concentration. Formula molarity = moles solute liters solution  How could you hate something that is this cute???

10. Molarity: Example What is the molarity of sugar in a typical can of cola? A cola has a volume of about 335mL and of that, about 36g is sugar (formula C 6 H 12 O 6.) moles sugar = 36g sugar | 1mol sugar = 0.20mol | 180.18g sugar Volume solution = 335mL (1L/1000mL) = 0.335L molarity = moles solute volume solution molarity = 0.20mol = 0.60mol/L = 0.60M 0.335L

11. Molarity: You Try What is the molarity of sweetener in a typical can of diet cola? A diet cola has a volume of about 335mL and of that, about 0.2g is sweetener (molar mass of about 294.3g/mol) moles swtnr = 0.2g swtnr | 1mol swtnr = 0.00068mol | 294.3g swtnr Volume solution = 335mL (1L/1000mL) = 0.335L molarity = moles solute volume solution molarity = 0.00068mol = 0.0020mol/L = 0.0020M 0.335L