April 03, 2013 Factors That Affect Solubility A) Temperature The solubility of most solids increases with S D temperature I L Higher temperature makes it easier to O S break the intermolecular forces between the solute and solvent S D The solubility of most liquids is NOT greatly I U affected by temperature Q I L April 03, 2013 The solubility of gases decreases as S E temperature increases S A •higher temperatures increases the energy G of the gas molecules so they can escape from solution Solubility Curves Tell us the mass of solute that will dissolve in 100g of water over a range of temperatures. On a solubility curve, the lines indicate the concentration of a saturated solution - the maximum amount of solute that will dissolve at that speciNic temperature. April 03, 2013 Let's Try Reading a Solubility Chart What mass of solute will dissolve in 100g of water at the following temperatures. 1. KNO3 at 70℃ 2. NaCl at 100℃ April 03, 2013 3. NH4Cl at 90℃ Which solute has the greatest solubility at 15˚C? April 03, 2013 What term - saturated, unsaturated, or supersaturated - best describes: ▪ a solution that contains 70g of NaNO3 per 100 mL H2O at 30°C ▪ a solution that contains 60g of dissolved KCl per 100 mL H2O at 80°C April 03, 2013 Factors That Affect Solubility B) Pressure The solubility of liquid and solid solutes is not inNluenced by temperature The solubility of gas solutes increases as the pressure increases (more molecules are "pushed" into solution) April 03, 2013 Factors That Affect Solubility C) Polarity of the Solute and Solvent 'Like Dissolves Like' -polar solutes have high solubility in polar solvents -polar solutes have low solubility in non-polar solvents -non-polar solutes have high solubility in non-polar solvents -non-polar solutes have low solubility in polar solvents Things to remember: -water is a polar solvent -hydrocarbons are non-polar -generally molecular compounds with oxygen in them are polar, and dissolve well in water April 03, 2013 An oil slick miscible liquids mix in all proportions (i.e. water and methanol) immiscible liquids do not mix (i.e. oil and water) April 03, 2013 D) Elements have low solubility in water (except for oxygen and the halogens) Example: Which would have the greatest solubility in water? Methane Methanol Mercury April 03, 2013 Practice: Read Textbook p. 176 - 183 Questions p. 183 # 1-7.