Chapter 15 Notes 1

Chapter 15: Aqueous Equilibria: Acids and Bases1. acid/base

characteristicsreactions (Arrhenius, Bronsted-Lowry, gas formation)hydronium ionpolyprotic, amphiprotic acidsconjugate pairsstrong vs. weak acids/bases

2. water autoionization, KW, pH and pOH3. measuring pH4. pH of solutions of strong acids/bases (calculations)5. weak acids

equilibria & Ka; calculations (pH from Ka and Ka from pH); %ionization; polyprotic acids

6. weak basescalculationsrelationship to Ka

7. saltsreactionscalculations

Chapter 15 Notes 2

Chapter 15: Aqueous Equilibria: Acids and Bases8. factors affecting acid/base strength9. Lewis acids/bases

1. acids & bases: characteristics Acids Bases

taste sour taste bitter

corrosive to metal feel slippery

aqueous acids conduct(electrolytes)

aqueous bases conduct(electrolytes)

acids turn litmus red bases turn litmus blue

acids: rainwater, coffee, fruit, carbonated water, vinegar, stomachneutral: blood, tears, saliva, milkbases: ammonia, lime water, borax, baking soda, lye, soap

Chapter 15 Notes 3

1. acids & bases:reactions1. Arrhenius acid/base reaction:

acid donates H1+ and base donates OH1-

general reaction: acid+basesalt+waterexamples:

HCl(aq)+NaOH(aq) NaCl(aq)+H2O(l)

HNO3(aq)+KOH(aq)

net ionic equation:

what about NH3? and Na2CO3? both are bases - how to understand?

2. Bronsted-Lowry reaction: more generalacid supplies H1+ and base grabs H1+

acid must have H1+ to donate and base must have lone pair of e1-

Chapter 15 Notes 4

1. acids & bases:reactions2. Bronsted-Lowry reaction: more general

acid supplies H1+ and base grabs H1+

acid must have H1+ to donate and base must have lone pair of e1-

examples: (identify the acid and base in each)CO3

2-(aq)+HCl(aq)HCO31-(aq)+Cl1-(aq)

HSO31-(aq)+H2O(l)

HBr(aq)+NH3(aq)

HNO3(aq)+CH3NH2(aq)

Chapter 15 Notes 5

1. acids & bases:reactions

•HCN & H2S: solubility in water low; gaseous HCN & H2S bubble out of sol’n at high concentrations•H2CO3 and H2SO3: decompose at high concentrationsexample:

HCl(aq)+HS1-(aq)H2S(g)+Cl1-

HBr(aq)+CN1-(aq)

HCO31-(aq)+HNO3(aq) H2CO3(aq)+NO3

1-(aq)

H2O(l)+CO2(g)

hydronium ion: H3O1+; hydrated H1+ [H(H2O)n1+, where n=1,2,3...]

polyprotic: can donate >1 H1+; H2SO4, H2CO3, H3PO4, H2Samphiprotic: can donate and accept H1+: H2O, HCO3

1-, HS1-, H2PO4-,

HPO42-,

Chapter 15 Notes 6

1. acids & bases:conjugate pairs: acid/base pairs that differ by transfer of H1+

examples- acid/base: H2O/OH1-; HC2H3O2/C2H3O21-; HCl/Cl1-;

name the conjugate acid of: H2O HS1-

NO31- Br1-

CH3NH2

name the conjugate base of: H3O1+ H3PO4

CO32-

strong vs. weakstrong: strong electrolyte, dissociates 100% in water

in water, exists as:

weak: weak electrolyte, dissociates <10% in waterin water, exists as:

driving force in acid/base reactions: 1. from strong to weak2. strong acids, bases are dissociated, weak acids, bases are molecular

Chapter 15 Notes 7

Chapter 15 Notes 8

1. acids & bases:strong vs. weak

example: predict the products, then predict whether the reaction goes left, right, or “can’t tell”

HCl(aq)+NO2-1

Br1-(aq)+NH41+(a q)

HC2H3O2(aq)+HS1-(aq)

NO31-(aq)+CH3NH3

1+(aq)