Notes Chapter 9 Book chapter 7

9-1 Nature of Solutions *Solution: p229 homo mixture in which one subst is dissolved in another subst ” Well mixed ”

-Properties of Solution -2 parts make up a solution *Solute: subst that is dissolved *Solvent: the subst that does the dissolving

-the solvent is usually a liquid ex: water(aqueous solution) *Tincture: when alcohol is the solvent in the solution

-more properties of solutions 1.Partic are indiv atoms, ions, or molecules 2.Liquid solution appears clear

3. Cannot be easily separated by simple means such a filtering 4. Solute molecules are evenly spread among solvent molecules(all parts are ident)

-Conductivity of Solutions -good conductor if it contains ions -nonconductor if it does not contain ions *Dissociation: separation of ions from a cmpnd during solution

*Electrolytes: aqueous solution that conducts electricity -usually ionic cmpnds *Nonelectrolytes: not conduct ele -usually covalent cmpds

*Ionization: formation of ions from solute molecules by the action of a solvent

-Model of the solution process 1.Solute part are separated from the surface of the solid solute(Dissolving) -endothermic(takes up nrg)

2. Solvent molecules are moved apart to allow solute molecules to enter the liquid surrounding the solid solute -endothermic

3. Solute molecules are attracted to solvent molecules -exothermic

9-2 Making Solutions

-Types of Solutions *miscible: 2 liquids that dissolve in each other ex: water and alcohol -alloy: solutions of solids in solids

-Rate of Solution -Ways to increase the rate of dissolving the solute – pp Heat it 2. Stir it 3. Crush it

-Solubility -Measure of how much of a solute can be dissolved in a given amnt of solvent under certain conditions pp239

-Solubility -solubility depends on the nature of the solute and solvent

-Solubility -it is the mass of solute that can be dissolved in a definite amnt of solvent at a spcfc temp -factors that effect solubility 1.Temp 2. Pressure

-temp ~solubility is increased in solids when temp is raised ~solubility is decreased in gases when temp is raised

ex: graph demo -pressure ~solid and liquid practically no effect ~gases dissolved in liquids, higher pressure higher solubility; and vise versa

*Effervescence: escape of gas from a liquid solution

-Concentration of Solutions pp240 *amnt of solute dissolved in a certain amnt of solvent *Concentrated: much solute *Dilute: little solute -also can be described as saturated, unsaturated, supersat

1. Saturated Solutions *contains all the solute it can possibly hold at a given temp -temp must always be given

2. Unsaturated Solution *contains less solute than it can possibly hold at a given temp

3. Supersaturated Solution *holds more solute than is normal for that temp. -supersat solu: is unstable ex: p

9-3 Water-The Universal Solvent -most common subst on earth -65% of body mass *Insoluble: will not dissolve

-Structure of a Water Molecule -unequal sharing produces an uneven charge *Polarity: oppositely charged ends

-Polar and Nonpolar Molecules -Like dissolves Like -EX: Water Molecule Structure on board -ex: p683

-Water Quality -the taste, odor, and appearance of water determines its quality *Hard water: contains large amnts of dissolved metal ions *Soft water: no metal ions

-Special Properties of Solutions -when a solute is dissolved in a liquid solvent, the freezing pnt is lowered/boiling pnt raises *Freezing pnt depression: *Boiling pnt elevation:

9-4 Suspensions and Colloids -physical prop determine whether a mixture is a suspension or a colloid

Suspension: p456 hetero mixture -solute part are larger than atoms, ions, or molecules -part. large enough to be seen without a microscope -will settle out over time

*Colloids: p455 homo mixture -not true solution -part. to small to be seen -does not separate -does scatter light

*Brownian Motion: constant movement of colloid particles

9-5 Acids -properties 1.pH below 7 2.taste sour

3.turns blue litmus paper red 4.reacts with metals to produce H gas 5.ionizes in water to produce H+ 6.proton donor

*Indicators: show definite color change when mixed with an acid ex: litmus, phenolphtalein *Hydronium ion H 3 O + : H+&water molecule

-Common Acids -Strong acids HCl H 2 SO 4 HNO 3

-Common Acids -Weak acids H 2 CO 3 H 3 BO 3 HC 2 H 3 O 2

9-6 Bases -properties 1.taste bitter 2.slippery to touch

9-6 Bases 3.turn litmus from red to blue 4.turn phenolphthalein pink 5.dissolve fats and oils 6.contain hydroxide ions(OH-)

9-7 Acids and Bases in Sol.: Salts *pH: measure of the hydronium ion (H 3 O) -indicates how acidic the solution is

9-7 Acids and Bases in Sol.: Salts - 0<7 = acid - 7>14 = base - 7 = neutral

-Determining Solution pH -by using an indicator ex: pH, litmus, phen, methyl orange, bromthyol blue

-Formation of Salts -acid + base -> salt + water -*neutralization: -*precipitate: -a solid -*precipitation: - process of forming a solid -Is a 2Bl replacement rxn