SolutionsSolutions

Chapter 13 & 14Chapter 13 & 14

SolutionSolution

A uniform mixture that may contain solids, A uniform mixture that may contain solids, liquids, or gasesliquids, or gases

Also called a homogeneous mixtureAlso called a homogeneous mixture Composed of a solute & solventComposed of a solute & solvent

Solute: substance that dissolvesSolute: substance that dissolves Solvent: dissolving mediumSolvent: dissolving medium

The most common solvent is water.The most common solvent is water.

SOLUTE + SOLVENT SOLUTE + SOLVENT SOLUTION SOLUTION

SolubilitySolubility

The maximum amount of solute that will The maximum amount of solute that will dissolve in a given amount of solventdissolve in a given amount of solvent

Solubility INCREASES as temp increasesSolubility INCREASES as temp increases Solubility DECREASES as pressure Solubility DECREASES as pressure

increasesincreases Solubility INCREASES as surface area Solubility INCREASES as surface area

increasesincreases

Solutions…Solutions…

Saturated solution: contains the maximum Saturated solution: contains the maximum amount of dissolved solute for a given amount of dissolved solute for a given amount of solventamount of solvent

Unsaturated solution: contains less Unsaturated solution: contains less dissolved solute than a saturated solutiondissolved solute than a saturated solution

Supersaturated solution: contains more Supersaturated solution: contains more dissolved solute than a saturated solutiondissolved solute than a saturated solution

A substance that dissolves in a substance is A substance that dissolves in a substance is soluble.soluble.

Ex. Sugar is soluble in waterEx. Sugar is soluble in water

A substance that does not dissolve in a A substance that does not dissolve in a solvent is insoluble.solvent is insoluble.

Ex. Sand is insoluble in waterEx. Sand is insoluble in water

Two liquids that are soluble in each other Two liquids that are soluble in each other are miscible.are miscible.

Ex. Water & acetic acid are miscibleEx. Water & acetic acid are miscible

Two liquids that are insoluble in each other Two liquids that are insoluble in each other are immiscible.are immiscible.

Ex. Oil & vinegar are immiscibleEx. Oil & vinegar are immiscible

Concentration: a measure of how much solute is Concentration: a measure of how much solute is dissolved in a solutiondissolved in a solution

Concentrated solution: contains a large amount of Concentrated solution: contains a large amount of solutesolute

Dilute solution: contains a small amount of soluteDilute solution: contains a small amount of solute

Expressing ConcentrationExpressing Concentration

Some common ways to express Some common ways to express concentration are:concentration are:

Percent by massPercent by mass Percent by volumePercent by volume Molarity Molarity Molality Molality

Percent by massPercent by mass

Describes solutions in which a solid is Describes solutions in which a solid is dissolved in a liquiddissolved in a liquid

% by mass= % by mass= mass of solute mass of solute x 100 x 100

mass of solutionmass of solution

Mass of solution= mass of solute + mass of solventMass of solution= mass of solute + mass of solvent

Percent by volumePercent by volume

Describes solutions in which both solute & Describes solutions in which both solute & solvent are liquidssolvent are liquids

% by volume= % by volume= volume of solute volume of solute x 100 x 100

volume of solutionvolume of solution

ProblemProblemFind the percent by mass of a Find the percent by mass of a

solution containing 50g of NaCl solution containing 50g of NaCl dissolved in 100g of water.dissolved in 100g of water.

MolarityMolarity

Molarity (M)= Molarity (M)= moles of solute moles of solute

liter of solutionliter of solution

ProblemProblemYou have 3.50L of solution that You have 3.50L of solution that

contains 90.0g of sodium chloride, contains 90.0g of sodium chloride, NaCl. What is the molarity of the NaCl. What is the molarity of the

solution?solution?

DilutionDilution

A concentrated solution can be diluted by A concentrated solution can be diluted by adding more solvent to the solution.adding more solvent to the solution.

MM11VV11 = M = M22VV22

ProblemProblemWhat volume is needed to dilute What volume is needed to dilute 3L of a 12M HCl solution to 2M 3L of a 12M HCl solution to 2M

HCl?HCl?

MolalityMolality

Molality (m)= Molality (m)= moles of solutemoles of solute

kg of solventkg of solvent

ProblemProblemA solution was prepared by A solution was prepared by

dissolving 17.1g of sucrose (table dissolving 17.1g of sucrose (table sugar, Csugar, C1212HH2222OO1111) in 125g of water. ) in 125g of water.

Find the molality of this solution.Find the molality of this solution.

Colligative propertiesColligative properties

Solutes affect some of the physical Solutes affect some of the physical properties of their solvents. These properties of their solvents. These properties are called colligative properties.properties are called colligative properties. Adding a solute to a solvent LOWERS the Adding a solute to a solvent LOWERS the

vapor pressure.vapor pressure. Adding a solute to a solvent RAISES the Adding a solute to a solvent RAISES the

boiling point.boiling point. Adding a solute to a solvent LOWERS the Adding a solute to a solvent LOWERS the

freezing point.freezing point.