Mixtures (Solutions) Heterogeneous Homogeneous Solution Heterogeneous colloid Heterogeneous suspension
Colloid Solution
+ = = + Solutions Salt water Carbonated water Solution Solute Solvent Most common solvent = water Solution with water as solvent is aqueous solvent
Solvation Water molecules in continuous motion http://www.chem.iastate.edu/group/Greenbowe/sections/projectfolder/flashfiles/thermochem/solutionSalt.html Water molecules in continuous motion Water molecules collide with crystals if solid Solvent water molecules attract the solute ions (Na+, Cl-) As individual ions break away from the crystal, the sodium chloride dissolves
Dissolving Like dissolves like nonpolar Like dissolves like Solute and solvent need to have similar polarities to be soluble Polar Polar dissolves polar Nonpolar dissolves nonpolar Polar dissolves ionic
Rate of Dissolving Most often increases with: Stirring (agitation) Temperature Surface area Contact of solute with solvent Faster b/c more surface area
Solubility The amount of substance that dissolves in a given quantity of solvent at a given temperature. Saturated Contains maximum amount of solute for given amount of solvent at given temperature Some solute particles out of solution Unsaturated Solution contains less solute than saturated solution All solute particles in solution
Supersaturated http://www.youtube.com/watch?v=0wifFbGDv4I
Solubility of Gas Gases more soluble at lower temperatures Gases more soluble at higher pressures Soda has large amounts of CO2 dissolved in water
Molarity Molarity (M) = (moles of solute)/(Liter of solution) Measures concentration Practice: If 44 grams of sodium fluoride are dissolved to make a 3.5M solution, what is the volume of the solution?
Dilutions To dilute a solution, more SOLVENT is added Moles of SOLUTE is the same Moles before = moles after M1V1 = M2V2 Practice: How many liters of 15 molar HCl are need to make 400 mL of a 0.4 molar solution of HCl?