review chapter 8 & 9:
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Review Chapter 8 & 9:. General, Organic, & Biological Chemistry Janice Gorzynski Smith. Chapter 8 & 9 Concepts. Identify the solvent and solute in a solution Like dissolves like, predict which molecules will form solutions Predict the effect of temperature or pressure on a solution - PowerPoint PPT PresentationTRANSCRIPT
Review Chapter 8 & 9:
General, Organic, & Biological ChemistryJanice Gorzynski Smith
2
Chapter 8 & 9 Concepts
Identify the solvent and solute in a solution Like dissolves like, predict which molecules will form solutions Predict the effect of temperature or pressure on a solution Perform concentration calculations & conversions Perform dilution calculations Predict relative changes in colligative properties between multiple
solutions Understand osmotic pressure & how your kidney’s work. Identify an acid/base reaction, the acid, base, conjugate acid/base Caculate Ka, Kb
Use Kw to determine concentration of H3O+ or OH-
Discuss how water acts as both an acid and a base Perform titration calculations Communicate how a buffer prevents large pH changes
CH 8 Equations & Conversions
Molarity = moles of solute (mol)
V of solution (L)
M1V1 = M2V2
CH 9 Equations & Conversions
Ka =[H3O+][ ]A −
[HA]
Kb = [OH- ][BH+][ B]
Kw = [H3O+][OH−] = 1.0 x 10−14
pH = -log[H3O+]
•Acidic solution: pH < 7 [H3O+] > 1 x 10−7
•Basic solution: pH > 7 [H3O+] < 1 x 10−7
•Neutral solution: pH = 7 [H3O+] = 1 x 10−7
Solutions, Solubility, & Concentration
1. The solute is the substance present in a lesser amount.
2. The solvent is the substance present in a larger amount.
Solubility is the amount of solute that dissolves in a given amount of solvent. REMEMBER: LIKE DISSOLVES LIKE.
In aqueous or liquid phase solutions solubility increases with increasing temperature Gases dissolved in liquids increase solubility with decreasing temperature and increasing pressure
Communicate how much of a solute is dissolved in a solvent using concentration:
% w/v % v/v % mass / mass ppm Molarity initial values final values
M1V1 = M2V2
Dilution: Adding more solvent to the initial solution. The number of moles solute DOES NOT CHANGE.
Colligative PropertiesColligative properties are properties of a solution that depend on the
concentration of the solute but not its identity.
One mole of any nonvolatile solute raises the boiling point of 1 kg of H2O the same amount, 0.51 oC.
One mole of any nonvolatile solute lowers the freezing point of 1 kg of H2O by the same amount,1.86 oC.
Apply pressure to reverse osmosis. This is how our
kidneys filter blood
Reverse Osmosis
Acids / Bases•A Brønsted–Lowry acid is a proton (H+) donor.
•A Brønsted–Lowry base is a proton (H+) acceptor.
H A + B A − H B++
gain of H+
acid base conjugatebase
conjugateacid
loss of H+
H O H
H2O as a base
add H+
H O H
H +
conjugate acidH2O as an acid
H O−
Conjugate base
remove H+
Strong:
Weak:
Kw = [H3O+][OH−]
Acid / Base Equilibrium & pH
H3O+(aq) + (aq) HA(g) + H2O(l) A −
Ka =[H3O+][ ]A −
[HA]
pH = -log[H3O+]
OH- (aq) + BH+ (aq) B (g) + H2O(l)
Kb = [OH- ][BH+][ B]
Base dissociationconstant
acid dissociationconstant
Low pH (0 ~ 7)[H3O+] high
Acidic Conditions
High pH (7 ~ 14)[H3O+] low
Basic Conditions
Common Acid / Base Reactions
Neutralization reaction: An acid-base reaction that produces a salt and water.
H+(aq) + OH− (aq) H—OH(l)
H+(aq) + HCO3−(aq)
H2O(l) + CO2(g)
H2CO3(aq)
A bicarbonate base, HCO3−, reacts with one H+ to form carbonic acid, H2CO3.
A carbonate base, CO32–, reacts with two H+ to form carbonic acid, H2CO3.
2 H+(aq) + CO32–(aq)
H2O(l) + CO2(g)
H2CO3(aq)
Titration
AH + B A- + BH+
Acid + Base Conjugate Base + Conjugate Acid
Moles ofbase
Volume ofacid
mole–moleconversion
factor
M (mol/L)conversion
factor
Moles ofacid
Volume of base
M (mol/L)conversion
factor[1]
[2]
[3]
Buffers
[ ]A −
[HA]=[H3O+] xKapH of buffer = -log[H3O+] where