Upcoming SlideShare
×

316 views

Published on

• Full Name
Comment goes here.

Are you sure you want to Yes No
• Be the first to comment

1. 1. SOLUTIONS
2. 2. DEFINITION • a mixture where the components are uniformly intermingled • a mixture that is homogeneous
3. 3. TYPES • Gaseous solution • Liquid solution • Solid solution
4. 4. Recall Solute • what is dissolved in a solution Mass • a measure of the amount of matter in an object (g or kg) Volume • measures the size of an object using length measurements in three dimensions (ml or L)
5. 5. Recall Mole (mol) • also known as Avogadro's Number • number that is used in making calculations involving atoms and molecules • 1 mol is equal to 6.022 x 1023 atoms or molecules • Molar Mass (MM) of elements and compounds is the mass, in grams, equal to the atomic and formula masses of those elements and compounds. The unit of Molar Mass is grams/mole
6. 6. Practice Calculate the molar mass of the following: • CO2 = 44.01 grams/mole • H2O = 18.02 grams/mole • NaCl = 58.44 grams/mole
7. 7. CONCENTRATION Relative Amounts of Solute and Solvent in a Solution
8. 8. Ways to Express the Relative Amounts of Solute and Solvent in a Solution • Percent concentration (by mass; by volume) • Molarity (M) • Molality (m) • Mole fraction (X)
9. 9. ● Percent Composition (by mass; by volume) We need two pieces of information to calculate the percent by mass of a solute in a solution: • mass/volume of the solute in the solution • mass/volume of the solution
10. 10. By mass: • % (w/w) = By volume: • % (v/v) = 100x solutionmass solutemass 100x solutionvolume solutevolume ● Percent Composition (by mass; by volume)
11. 11. Practice • 10 g salt and 70 g water are mixed to make a solution. Find the concentration of the solution by percent mass. 12.5 %
12. 12. Practice • The concentration by volume of a 1.5 L NaCl solution is 40 %. Find the amount of solute in this solution. 0.6 L
13. 13. ● Molarity (M) Molarity tells us the number of moles of solute in exactly one liter of a solution. We need two pieces of information to calculate the molarity of a solute in a solution: • moles of solute present in the solutio • volume of solution (in liters) containing the solute
14. 14. ● Molarity (M)
15. 15. Practice • What is the molarity of a solution that contains 1.724 moles of H2SO4 in 2.50 L of solution? 0.690 M H2SO4
16. 16. Practice • What is the molarity of a solution prepared by dissolving 25.0 g of HCl (g) in enough water to make 150.0 mL of solution? 4.57 M HCl
17. 17. ● Molality (m) Molality, m, tells us the number of moles of solute dissolved in exactly one kilogram of solvent. We need two pieces of information to calculate the molality of a solute in a solution: • moles of solute present in the solution • mass of solvent (in kilograms) in the solution
18. 18. ● Molality (m) Recall: density of water = 1.00 g / mL or 1 kg/L
19. 19. Practice • Suppose you had 58.44 grams of NaCl and you dissolved it in exactly 2.00 kg of pure water. What would be the molality of the solution? 0.5 m
20. 20. Practice • 80.0 grams of glucose (C6H12O6, mol. wt = 180 g/mol) is dissolved in 1.00 L of water. What is its molality? 0.44 m
21. 21. ● Mole Fraction (X) The mole fraction, X, of a component in a solution is the ratio of the number of moles of that component to the total number of moles of all components in the solution. To calculate mole fraction, we need to know: • number of moles of each component present in the solution
22. 22. ● Mole Fraction (X) NOTE: The sum of the mole fractions for each component in a solution will be equal to
23. 23. Practice • A solution is prepared by mixing 25.0 g of water, H2O, and 25.0 g of ethanol, C2H5OH. Determine the mole fractions of each substance. XH2O = 0.71 XC2H5OH = 0.29
24. 24. COLLOIDS
25. 25. • a heterogeneous system in which one substance is dispersed (dispersed phase) as very fine particles in another substance called dispersion medium DEFINITION
26. 26. • the size of the dispersed molecule is larger than a simple molecule (having diameter between 1 to 1000 nm) but small enough to remain suspended
27. 27. • an intermediate state between suspensions and solutions
28. 28. THE TYNDALL EFFECT • colloidal suspensions exhibit light scattering • named after its discoverer, the 19th-century British physicist John Tyndall • a special instance of diffraction (bending of light) • often used as a measure of the existence of a colloid • visible in colloids as weak as 0.1 ppm (exception?)
29. 29. TYPES AND EXAMPLES based on physical state of dispersion medium and dispersed phase
30. 30. medium: SOLID phase: SOLID Gemstones Pearls Some coloured glass
31. 31. medium: SOLID phase: GAS Pumice Foam Rubber
32. 32. medium: SOLID phase: LIQUID Cheese Shoe polish Butter Jellies Jam
33. 33. medium: LIQUID phase: LIQUID Milk Hair Cream Cod liver oil
34. 34. medium: LIQUID phase: GAS Froth Soap lather Whipped cream
35. 35. medium: LIQUID phase: SOLID Paints Gum Muddy water
36. 36. medium: GAS phase: LIQUID Fog Clouds Insecticide spray
37. 37. medium: GAD phase: SOLID Smoke Dust
38. 38. medium: GAS phase: GAS
39. 39. At a glance MEDIUM PHASE SOLID LIQUID GAS SOLID Solis Sols gemstones, pearls, some coloured glass Gels cheese, butter, shoe polish, jellies, jam Solid Sols pumice, foam rubber LIQUID Sols gum, paint, muddy water Emulsion milk, hair cream, cod liver oil Foam froth, whipped cream, soap lather GAS Aerosol smoke, dust Aerosol clouds, spray, fog ---
40. 40. e o s