Solutions; Acids & Bases

Solubility A solute dissolves in a solvent A solute dissolves in a solvent –saturated, unsaturated, supersaturated Likes dissolve likes (based on polarity or charges) Likes dissolve likes (based on polarity or charges) Which salt is the most soluble at 25 C?

Colligative Properties Depend on the amount of solute dissolved and not the TYPE Depend on the amount of solute dissolved and not the TYPE 1) Vapor Pressure Lowering 2) Boiling Point Elevation 3) Freezing Point Depression

Concentration How much solute is dissolved in a solvent How much solute is dissolved in a solvent Molarity = moles / Liter Molarity = moles / Liter If 58.5 g of NaCl are dissolved in 650 mL of water, what is the molarity? If 58.5 g of NaCl are dissolved in 650 mL of water, what is the molarity? ML mol

Dilutions Adding solvent decreases the concentration Adding solvent decreases the concentration M 1 V 1 =M 2 V 2 M 1 V 1 =M 2 V 2 What volume of 12 M HCl is needed to make 250 mL of a 3.0 M solution? What volume of 12 M HCl is needed to make 250 mL of a 3.0 M solution?

Properties ACIDS Turn litmus red Turn litmus red Low pH Low pH Neutralize bases Neutralize basesBASES Turn litmus blue Turn litmus blue High pH High pH Neutralize acids Neutralize acids

Definitions Arrhenious Bronsted- Lowry ACID produce H + in solution proton (H + ) donor BASE produce OH - in solution proton acceptor

pH Problems pH = -log[H + ] pH = -log[H + ] –Brackets indicate molarity pH + pOH = 14 pH + pOH = 14 What is the pH of a M HCl solution? What is the pH of a M HCl solution? What is the pOH? What is the pOH?

Indicators Change colors at specific pH Change colors at specific pH Which indicator could be used in a titration where the endpoint occurs at a pH of 8? Which indicator could be used in a titration where the endpoint occurs at a pH of 8?