1 / 18

Concentration Day 2: Chapter 14

Concentration Day 2: Chapter 14. CONCENTRATION. The amount of solute present in a set amount of solvent or total solution. CONCENTRATION. Mola r ity (M or mol/ L ) Mola l ity ( m or mol/ Kg ) Weight percent (%) mole fraction ( c ). Weight Percent. CONCENTRATION. Weight Percent

zazu
Download Presentation

Concentration Day 2: Chapter 14

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. ConcentrationDay 2: Chapter 14

  2. CONCENTRATION • The amount of solute present in a set amount of solvent or total solution.

  3. CONCENTRATION • Molarity (M or mol/L) • Molality (m or mol/Kg) • Weight percent (%) • mole fraction (c)

  4. Weight Percent

  5. CONCENTRATION • Weight Percent • % = mass solute (g) x 100 total mass solution (g) What percent of Soda is sugar? 43 g sugar/355g total = .12 (100) = 12% What percent of Yogart is sugar? 25 g/ 170 g total = .15 (100) = 15%

  6. CONCENTRATION parts per million (ppm) 7ppm is = 7 grams of solute One million grams total Used to measure small levels of trace solutes in water (dissolved oxygen)

  7. CONCENTRATION • Molarity (M) is measurement of concentration. • Molarity is the number of moles solute dissolved in oneliter of solution. M = mol solute total L solution

  8. Molarity Example What is the molarity of a solution that contains 1.8 mol of HCl in 500. mL of total solution M = molof HCl X M = 1.8 mol liters solution 0.500 L = 3.60 M or 3.6 mol/L 0f HCl

  9. Molarity Example How many moles of solute are present in 1.5 L of 0.20 M NaCl solution? M = mol of NaCl 0.20M = X mol liters solution 1.5 L = 0.30 moles of NaCl

  10. Molarity Example • How many grams of CuCl2 should be used to prepare .250 L of a 0.40 M solution? • M = moles of CuCl2.40 M= x moles liter solution .250 L = .10 moles of CuCl2 Change moles to grams: Moles X Molar mass = Mass .10 moles x 134 grams CuCl2= 13.4 g 1 mole CuCl2

  11. Concentration Units An IDEAL SOLUTION is one where the properties depend only on the concentration of solute. Need conc. units to tell us the number of solute particles per solvent particle. The unit “molarity” does not do this!

  12. Concentration Units MOLE FRACTION, X For a mixture of A, B, and C What fraction of Soda is sugar? 43 g sugar: 300.g water = 0.13 mol: 17 mol = X = 0.13/17.13 = 0.0073 Xwater = 17/17.13 = 0.99

  13. MOLALITY, m What molal of sugar (342 g/mol) is in Soda ? 43 g sugar & 300.g water 0.13 mol & 0.300 kg m = 0.13 mol / 0.30 Kg = 0.43m

  14. Calculating Concentrations Dissolve 62.1 g (1.00 mol) of ethylene glycol in 250. g of H2O. Calculate mol fraction, molality, and weight % of glycol.

  15. Calculating Concentrations Dissolve 62.1 g (1.00 mol) of ethylene glycol in 250. g of H2O. Calculate X, m, and % of glycol. 250. g H2O = 13.9 mol X glycol = 0.0672

  16. Calculating Concentrations Dissolve 62.1 g (1.00 mol) of ethylene glycol in 250. g of H2O. Calculate X, m, and % of glycol. Calculate molality Calculate weight %

More Related