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Chapters 22: SolutionsChapters 22: Solutions
Section 1: How Solutions FormSection 1: How Solutions Form
A. Solutions and Other MixturesA. Solutions and Other Mixtures
All matter is either a pure substance or a mixtureAll matter is either a pure substance or a mixture Types of mixturesTypes of mixtures
Homogeneous = Homogeneous = solutionsolution; ;
same composition throughoutsame composition throughout Heterogeneous = not the same Heterogeneous = not the same
composition throughoutcomposition throughout
Pure substancesPure substances ElementsElements CompoundsCompounds
B. SolutionsB. Solutions
Solution is a homogeneous mixtureSolution is a homogeneous mixture Made up of solute and solventMade up of solute and solvent
Solute = what is dissolvedSolute = what is dissolved Solvent = substance doing the dissolvingSolvent = substance doing the dissolving
Most common solvent?Most common solvent? Water! Why?Water! Why?
B. Solution ExamplesB. Solution Examples
KoolAidKoolAid
Unsweet teaUnsweet tea
Sweetened teaSweetened tea
SaltwaterSaltwater
C. DissolvingC. Dissolving
Molecules are constantly in motion Molecules are constantly in motion according to…according to… Kinetic Theory of MotionKinetic Theory of Motion
When particles collide, energy is When particles collide, energy is transferredtransferred
When ionic compounds dissolve in water, When ionic compounds dissolve in water, ions separate in solutionions separate in solution Example: NaCl in water becomes NaExample: NaCl in water becomes Na++ and Cl and Cl--
D. SolventsD. Solvents
Water is universal solvent Water is universal solvent b/c of its b/c of its polaritypolarity
If something can dissolve If something can dissolve in something else, it is said in something else, it is said to be to be solublesoluble
If it cannot dissolve, it is If it cannot dissolve, it is said to be said to be insolubleinsoluble
““Like dissolves like”Like dissolves like”
D. SolventsD. Solvents
NONPOLAR
NONPOLAR
POLAR
POLAR
““Like Dissolves Like”Like Dissolves Like”““Like Dissolves Like”Like Dissolves Like”
E. SolvationE. Solvation
Solvation – Solvation – the process of dissolvingthe process of dissolving
solute particles are separated and solute particles are separated and pulled into solutionpulled into solution
solute particles are surrounded by solute particles are surrounded by solvent particlessolvent particles
E. SolvationE. Solvation
DissociationDissociation separation of an separation of an ionic ionic
solidsolid into aqueous into aqueous ionsions
NaCl(s) Na+(aq) + Cl–(aq)
E. SolvationE. Solvation
StrongElectrolyte
Non-Electrolyte
solute exists asions only
- +
salt
- +
sugar
solute exists asmolecules
only
- +
acetic acid
WeakElectrolyte
solute exists asions and
molecules
F. Factors Affecting SolubilityF. Factors Affecting Solubility
Solubility = amount of a substance that will Solubility = amount of a substance that will dissolve in a liquiddissolve in a liquid
Smaller pieces of a substance dissolve Smaller pieces of a substance dissolve faster b/c of larger surface areafaster b/c of larger surface area
Stirring or shaking speeds dissolving b/c Stirring or shaking speeds dissolving b/c particles are moving faster and colliding particles are moving faster and colliding moremore
Heating speeds dissolving (see above)Heating speeds dissolving (see above) Not all substances dissolveNot all substances dissolve
F. SolubilityF. Solubility
Solids are more soluble at...Solids are more soluble at... high temperatures.high temperatures.
Gases are more soluble at...Gases are more soluble at... low temperatures &low temperatures & high pressures (Henry’s Law).high pressures (Henry’s Law). EXEX: nitrogen narcosis, the “bends,” soda: nitrogen narcosis, the “bends,” soda
G. SolubilityG. Solubility
Solubility CurvesSolubility Curves maximum grams of solute that will dissolve in maximum grams of solute that will dissolve in
100 g of solvent at a given temperature100 g of solvent at a given temperature varies with tempvaries with temp based on a saturated solnbased on a saturated soln
G. SolubilityG. Solubility
Solubility CurveSolubility Curve shows the shows the
dependence of dependence of solubility on solubility on temperaturetemperature
H. ConcentrationH. Concentration The more The more solutesolute or less or less solventsolvent in a in a
solution, the more solution, the more concentratedconcentrated the the solution becomessolution becomes
The less The less solutesolute or more or more solventsolvent in a in a solution, the more solution, the more dilutedilute the solution the solution becomesbecomes
A A saturatedsaturated solution is one in which no solution is one in which no more solute can dissolvemore solute can dissolve
A A supersaturatedsupersaturated solution is one in which solution is one in which the solvent is heated and can dissolve the solvent is heated and can dissolve more solutemore solute
H. ConcentrationH. Concentration
SATURATED SOLUTION
no more solute dissolves
UNSATURATED SOLUTIONmore solute dissolves
SUPERSATURATED SOLUTION
becomes unstable, crystals form
concentration
Chapter 23Chapter 23
Acids, Bases & SaltsAcids, Bases & Salts
Review – Acid NamesReview – Acid NamesHClHClHH22SOSO44
HNOHNO33
HH22SOSO33
HCHC22HH33OO22
Hydrochloric acidHydrochloric acidSulfuric acidSulfuric acidNitric acidNitric acidSulfurous acidSulfurous acidAcetic acidAcetic acid
What are acids?What are acids? Compounds that donate HCompounds that donate H++ ions in water ions in water Taste sourTaste sour Concentrated acids can burn skin and Concentrated acids can burn skin and
eyeseyes On pH scale, found below 7On pH scale, found below 7
Stronger acids closer to 1Stronger acids closer to 1 Examples: citric acid, stomach acid, soda, Examples: citric acid, stomach acid, soda,
coffeecoffee
What are bases?What are bases?
Compounds that donate OHCompounds that donate OH-- ions in water ions in water Taste bitter, are slipperyTaste bitter, are slippery Can be dangerous as wellCan be dangerous as well Often cleaning productsOften cleaning products pH above 7pH above 7
Stronger bases closer to 14Stronger bases closer to 14 Examples: bleach, baking Examples: bleach, baking
soda, antacidssoda, antacids
NeutralNeutral
All neutral solutions have a pH of 7All neutral solutions have a pH of 7
Water is a neutral solutionWater is a neutral solution
pH ScalepH Scale
NeutralizationNeutralization Reaction between an acid and a base to Reaction between an acid and a base to
produce water and a saltproduce water and a salt
HH++ + OH + OH-- H H22OO
Example:Example:
HCl + NaOH HCl + NaOH H H22O + NaClO + NaCl
Do not always produce a neutral solutionDo not always produce a neutral solution
IndicatorsIndicators
• Chemical dyes whose color are affected by acidic and basic solutions are called acid-base indicators
SummarySummary
electrolyteselectrolytes electrolyteselectrolytes
turn litmus redturn litmus red
sour tastesour taste
Donate HDonate H++ (HCl) (HCl) Donate OHDonate OH-- (NaOH) (NaOH)
turn litmus blueturn litmus blue
bitter tastebitter taste
vinegar, milk, soda, vinegar, milk, soda, apples, citrus fruitsapples, citrus fruits
ammonia, lye, antacid, ammonia, lye, antacid, baking sodabaking soda