Chapter 7: SolutionsChapter 7: Solutions

Section 1: Solutions and Other Section 1: Solutions and Other MixturesMixtures

Heterogeneous: a mixture with no fixed composition, Heterogeneous: a mixture with no fixed composition, not the same throughoutnot the same throughout

Examples:Examples: Suspension: particles are more or less evenly Suspension: particles are more or less evenly

dispersed, particles can settle and even be filtered. dispersed, particles can settle and even be filtered. Ex: orange juiceEx: orange juice

Colloid: like a suspension but the particles are Colloid: like a suspension but the particles are smaller (and scatter light). Ex: paintsmaller (and scatter light). Ex: paint

Emulsions: droplets of fats or lipids dispersed in Emulsions: droplets of fats or lipids dispersed in water. Ex: creamwater. Ex: cream

Mixtures: (cont)(cont)Homogeneous Mixtures: Homogeneous Mixtures:

uniform, the same throughoutuniform, the same throughout Components: Components: solutesolute and and

solvent solvent like like saltsalt and and waterwater Solutions can be liquid, solid Solutions can be liquid, solid

or gasor gas Alloys are solutions of metalsAlloys are solutions of metals QuizQuiz Quiz 2Quiz 2

Examples of SolutionsExamples of Solutions gas in gasgas in gas air ( Nair ( N22, O, O22 , Ar, CO , Ar, CO22 , other , other

gases)gases)

gas in liquidgas in liquid soda pop (COsoda pop (CO22 in water) in water)

liquid in liquidliquid in liquid gasoline (a mixture of gasoline (a mixture of hydrocarbon compounds)hydrocarbon compounds)

solid in liquidsolid in liquid sea water ( NaCl and other salts in sea water ( NaCl and other salts in water)water)

gas in solidgas in solid HH22 in platinum or palladium in platinum or palladium

liquid in solidliquid in solid dental amalgams ( mercury in silver)dental amalgams ( mercury in silver)

solid in solidsolid in solid alloys: brass, (Cu/Zn), solder (Sn/Pb)alloys: brass, (Cu/Zn), solder (Sn/Pb)

Section 2: How substances dissolveSection 2: How substances dissolve

Water:Water: A common solventA common solvent Polar compounds like water, Polar compounds like water, dissolve ions and polar moleculesdissolve ions and polar molecules Hydrogen bonding occurs between water Hydrogen bonding occurs between water

molecules and helps to dissolve some molecules and helps to dissolve some polar molecular compoundspolar molecular compounds

Like dissolves like, nonpolar compounds Like dissolves like, nonpolar compounds dissolve nonpolar compoundsdissolve nonpolar compounds

Dissolving ProcessDissolving Process Solutes with a larger Solutes with a larger

surface area dissolve surface area dissolve faster faster

Stirring and shaking help Stirring and shaking help to increase solution rateto increase solution rate

An increase in An increase in temperature increases the temperature increases the solubility of some solidssolubility of some solids

Solutes can affect the Solutes can affect the physical properties of a physical properties of a solutionsolution

Section 3: Solubility and ConcentrationSection 3: Solubility and Concentration

Terms:Terms: SolubleSoluble InsolubleInsoluble UnsaturatedUnsaturated SaturatedSaturated SupersaturatedSupersaturated Solubility of substances (in grams) is often Solubility of substances (in grams) is often

measured in 100 g (or 100 mL) of watermeasured in 100 g (or 100 mL) of water

Factors affecting solubilityFactors affecting solubility

Substance dependent: some substances Substance dependent: some substances dissolve in water and some do notdissolve in water and some do not

Temperature affects solubilityTemperature affects solubility SolidsSolids GasesGases

Pressure affects solubility of gasesPressure affects solubility of gases

Solubility CurvesSolubility Curves

Solubility of GasesSolubility of Gases

Measuring solubilityMeasuring solubility

Concentration:Concentration: g/100 mL of solventg/100 mL of solvent Molarity: moles of solute/L of solutionMolarity: moles of solute/L of solution

• mol/L = Mmol/L = M• p 243p 243

Examples:Examples: