1. Concentrations of Solutions

2. What are the components of a Solution? Solute and Solvent

3. Do the components in a solution have differences?

4. Concentration of Solutions Refers to amount of solute dissolved in a unit amount of solvent or of solution. Expressed in: -Percent Composition (by mass or volume) -Molarity -Molality -Mole Fraction

5. Percent Composition Percent by Mass % by mass = Mass of solute X 100 Mass of solution Percent by Volume % by volume = Volume of solute X 100 Volume of solution Where: Mass/Vol. of sol’n = mass/vol. of solute + mass/vol. of solvent

6. 1. What is the mass percentage of a solution made by dissolving 4.0 g NaCl in 100.0 g of water? % by Mass = Mass of solute X 100 Mass of solution = 4.0 g NaCl X 100 100.0 + 4.0g = 0.03846 X 100 = 3.846 %

7. 2. A medical solution used is 0.9 % by mass of NaCl. How many grams of NaCl are present in 100.0 g of the solution? % by Mass = Mass of solute X 100 Mass of solution 0.9= (?) g NaCl X 100 100.0 g of solution = 0.9 g of NaCl

8. 3. Dimercaprol, a compound used as an antidote for mercury and arsenic poisoning, is prepared by mixing 100.0 mg of dimercaprol with 700.0 mg of peanut oil. What is the percent by mass of dimecaprol in this solution? % by Mass = Mass of solute X 100 Mass of solution = 100mg Dimercaprol X 100 100.0mg Dimeracprol + 700.00mg peanut oil = 100mg X 100 800mg Solution %= 12.5

9. 4. What is the mass percent of NaCl in a solution that is made by dissolving 12.0 g of NaCl in 60.0 g of H 2 O? % by Mass = Mass of solute X 100 Mass of solution = 12.0 g NaCl X 100 12.0g NaCl + 60.0 g H 2 O = 12.0 g NaCl X 100 72.0 g Solution %= 0.166 X 100 %= 16.6

10. 5. What is the volume of alcohol in 500 mL of wine which contains 12% alcohol by volume? What is its proof number? % by Mass = Volume of solute X 100 Vol. of solute + Vol. of solvent 12= (?) volume of alcohol X 100 500.0 mL wine 12= (?) volume of alcohol X 100 500.0 mL wine 6000mL = [(?) volume of alcohol] 100 100100 60mL= volume of alcohol

11. 6. A bottle of Lambanog is 80 proof. What is the percent by volume of alcohol in this bottle of Lambanog? Degree proof is twice the percent by volume. Therefore: an 80 proof alcohol contains 40% by volume of alcohol Thus: in every 100mL has 40mL of alcohol and 60mL water

12. Seatwork

13. 1. What is the mass percent of mothball in a solution that is made by dissolving 12g of mothball in 60.0 g of CCl 4 ?

14. 2. What is the percent volume of CCl4 in a solution that is made by dissolving 12ml of CCl4 in 1.0L of kerosene?

15. 3. What is the volume of CCl4 in a solution of 2.0L which contains 30% CCl4