Solutions; Acids & Solutions; Acids & BasesBases

Solubility Solubility

•A solute dissolves in a solventA solute dissolves in a solvent– saturated, unsaturated, saturated, unsaturated, supersaturatedsupersaturated

•Likes dissolve likes (based on Likes dissolve likes (based on polarity or charges)polarity or charges)

Which salt is the most soluble at 25 C?

Colligative PropertiesColligative Properties

•Depend on the amount of solute Depend on the amount of solute dissolved and not the TYPEdissolved and not the TYPE

1) Vapor Pressure Lowering1) Vapor Pressure Lowering

2) Boiling Point Elevation2) Boiling Point Elevation

3) Freezing Point Depression3) Freezing Point Depression

ConcentrationConcentration•How much solute is dissolved in a How much solute is dissolved in a solventsolvent

•Molarity = moles / LiterMolarity = moles / Liter

•If 58.5 g of NaCl are dissolved in If 58.5 g of NaCl are dissolved in 650 mL of water, what is the 650 mL of water, what is the molarity?molarity?

M L

mol

DilutionsDilutions

•Adding solvent decreases the Adding solvent decreases the concentrationconcentration

•MM11VV11=M=M22VV22

•What volume of 12 M HCl is What volume of 12 M HCl is needed to make 250 mL of a 3.0 needed to make 250 mL of a 3.0 M solution?M solution?

PropertiesProperties

ACIDSACIDS

• Turn litmus redTurn litmus red

• Low pHLow pH

• Neutralize basesNeutralize bases

BASESBASES

• Turn litmus blueTurn litmus blue

• High pHHigh pH

• Neutralize acidsNeutralize acids

DefinitionsDefinitions

ArrheniousArrhenious Bronsted-Bronsted-LowryLowry

ACIDACID produce Hproduce H++ in in solutionsolution

proton (Hproton (H++) ) donordonor

BASEBASE produce OHproduce OH- -

in in solutionsolution

proton proton acceptoracceptor

pH ProblemspH Problems

•pH = -log[HpH = -log[H++]]– Brackets indicate molarityBrackets indicate molarity

•pH + pOH = 14pH + pOH = 14

•What is the pH of a 0.0011 M What is the pH of a 0.0011 M HCl solution?HCl solution?

•What is the pOH?What is the pOH?

IndicatorsIndicators

•Change colors at specific pHChange colors at specific pH

•Which indicator could be used Which indicator could be used in a titration where the in a titration where the endpoint occurs at a pH of 8?endpoint occurs at a pH of 8?