1. TOPIC: Concentration and Dilution Do Now:

2. Parts of a Solution SoluteSolute = dissolved substance SolventSolvent = dispersing medium

3. We can determine how much solute and solvent make up a solution = CONCENTRATION Concentration = A measurement that describes how much solute is in a given amount of solvent or solution. Many, many different units to express concentration. Molarity Molarity PPM (parts per million) PPM (parts per million) % by mass % by mass % by volume % by volume

4. Molarity (M) Molarity (M) = moles of solute liters of solution liters of solution CAN USE THIS TO HELP CALCULATE CAN USE THIS TO HELP CALCULATE moles M liters

5. So why do aqueous solutions need.1M or 3M in front?!?!?!

7. Dilution -which one has a higher molarity?

8. Amount of solute is constant Amount of solvent increases Amount solute in concentrated solution EQUALS Amount solute in dilute solution Dilution = add water = less concentrated

9. Molarity C x Volume C = Molarity D x Volume D M C x V C = M D x V D (C = concentrated D = dilute)

10. 300ml of 2.5M NaOH is diluted to 750ml. Find the molarity of the diluted solution M C x V C = M D x V D 300ml x 2.5M = 750ml x M D 300ml 2.5M ?M 750ml water 1M So how much water did we have to add to delete the 2.5 M solution? 750 -300 _ 450ml

11. Example: We are doing a lab and the procedure calls for 300ml 1.2 M NaOH. However, all we have is a bottle of 5.5M NaOH. We have to dilute it!!!! The Equation: M C x V C = M D x V D 5.5 M x V C = 1.2 M x 300ml V1 = (1.2 M x 300 ml) 5.5 M So what does 65 ml tell us?! V1 = 0.065 L = 65 mL

12. To prepare the 1.2 M NaOH solution, you pour 65 mL of 5.5 M NaOH into your container and add water to get 300 mL final volume (300-65 = 235 ml water added)