1. Concentrations 12.4

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3. Colligative Properties Define: Properties that depend on the concentration – solute molecules – ions in solution Independent of the chemical identity of the solute

4. Concentration Define: amount of solute dissolved in a given quantity of solvent or solution. Examples of things that need to have the right concentration. – Pop-Paint – Perfume-soap

5. Molarity Define Moles of solute Liter of solution

6. What is the molarity of a solution made be dissolving 10 g NaCl in 50 mL of water?

7. Mass Percentage Mass of solute* 100 Mass of solution

8. What is the mass percentage of NaCl when 10 g are dissolved in 90 g of water?

9. How would you prepare 425 g of an aqueous solution containing 2.40% by mass of sodium acetate?

10. An experiment calls for 35.0 g of HCl that is 20.2% HCl by mass. How many grams of HCl is this? How many grams of H 2 O?

11. Molality Define: Moles of solute Kilogram of solvent

12. Glucose, C 6 H 12 O 6 is the body’s main source of energy. What is the molality of a solution containing 5.67 g of glucose dissolved in 25.2 g of water?

13. Find the molality of toluene in a solution that contains 35.6 g of toluene, C 6 H 5 CH 3 in 125g of benzene, C 6 H 6.

14. Mole fraction Define: Moles of substance A Total moles of solution

15. What is the mole fraction of glucose and water in a solution containing 5.67 g of glucose dissolved in 25.2 g of water?

16. What are the mole fractions of toluene and benzene in a solution that contains 35.6 g of toluene, C 6 H 5 CH 3 in 125 g of benzene, C 6 H 6.

17. Converting Molality to Mole Fraction An aqueous solution is 0.120 m glucose. What are the mole fractions of each component in the solution?

18. A solution is 0.120 m methanol dissolved in ethanol. Calculate the mole fractions of methanol, CH 3 OH and ethanol, C 2 H 5 OH in the solution

19. Mole fraction to Molality A solution is 0.150 mole fraction glucose and 0.850 mole fraction water. What is the molality of glucose in the solution?

20. A solution is 0.250 mole fraction methanol, and 0.750 mole fraction ethanol. What is the molality of methanol in the solution?

21. Converty Molality to Molarity An aqueous solution is 0.273 m KCl. What is the molar concentration of potassium chloride, KCl? The density of the solution is 1.011*10 3 g/L.

22. Urea, (NH2)2CO, is used as a fertilizer. What is the molar concentraion of an aqueous solution that is 3.42 m urea? The density of the solution is 1.045 g/mL.

23. Converting Molarity to Molality An aqueous solution is 0.907M Pb(NO 3 ) 2. What is the molality of Pb(NO 3 ) 2 in this solution? The density of the solution is 1.252 g/L.

24. An aqueous solution is 2.00 M urea. The density of the solution is 1.029 g/mL. What is the molal concentration of urea in the solution?

25. Homework 39 – 57 odds