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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
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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 • 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 • CaculateKa, 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
A− CH 9 Equations & Conversions [H3O+][ ] Ka= [HA] [OH- ][BH+] Kb = [ B] Kw = [H3O+][OH−] = 1.0 x 10−14 pH = -log[H3O+] • Acidic solution: pH < 7 [H3O+] > 1 x 10−7 • Neutral solution: pH = 7 [H3O+] = 1 x 10−7 • Basic solution: pH > 7 [H3O+] < 1 x 10−7
Solutions, Solubility, & Concentration Thesoluteis the substance present in a lesser amount. Thesolventis 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 decreasingtemperature and increasing pressure Communicate how much of a solute is dissolved in a solvent using concentration: % w/v % v/v % mass / mass ppm Molarity Dilution: Adding more solvent to the initial solution. The number of moles solute DOES NOT CHANGE. M1V1 = M2V2 initial values final values
Colligative Properties Colligative 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. Reverse Osmosis Apply pressure to reverse osmosis. This is how our kidneys filter blood
A− B Acids / Bases Strong: Weak: • A Brønsted–Lowry acid is a proton (H+) donor. • A Brønsted–Lowry base is a proton (H+) acceptor. gain of H+ H A + + H B+ conjugate acid acid base conjugate base loss of H+ + − H Kw = [H3O+][OH−] remove H+ add H+ H O H O H H O H Conjugate base H2O as a base conjugate acid H2O as an acid
A− A− Acid / Base Equilibrium & pH HA(g) + H2O(l) H3O+(aq) + (aq) [H3O+][ ] acid dissociation constant Ka= [HA] Low pH (0 ~ 7) [H3O+] high Acidic Conditions pH = -log[H3O+] B (g) + H2O(l) OH- (aq) + BH+ (aq) High pH (7 ~ 14) [H3O+] low Basic Conditions [OH- ][BH+] Base dissociation constant Kb = [ B]
Common Acid / Base Reactions Neutralization reaction: An acid-base reaction that produces a salt and water. H+(aq) + OH− (aq) H—OH(l) A bicarbonate base, HCO3−, reacts with one H+to form carbonic acid, H2CO3. H+(aq) + HCO3−(aq) H2CO3(aq) H2O(l) + CO2(g) A carbonate base, CO32–, reacts with two H+ to form carbonic acid, H2CO3. 2 H+(aq) + CO32–(aq) H2CO3(aq) H2O(l) + CO2(g)
Titration AH + B A- + BH+ Acid + Base Conjugate Base + Conjugate Acid mole–mole conversion factor [2] Moles of base Moles of acid M (mol/L)conversionfactor M (mol/L) conversion factor [3] [1] Volume of base Volume of acid
A− Buffers [HA] [H3O+] = Ka x pH of buffer = -log[H3O+] where [ ]