EXAM 3 REVIEW

notes 6.1-6.4, 7.1-7.5, and 8.1

6.1 bronsted lowery

1. acids ____ protons

2. bases ____ protons

1. donate

2. accept

6.1 the more stable the conjugate base the more ___ the acid

strong

6.1 counterions/spectater ions

mask charges (+ on a -)

first two tables of periodic tables

*sometimes halogens (Cl-, Br-, I-)

6.2 using pka values to compare strenghts

1. strong acid = ____ pka

2. weak acid = ___ pka

3. weaked pka =

4. strongest pka =

1. LOW

2. HIGH

3. 50

4. -10

6.2 pka to pkb

1. weaker base = ___ stable

2. stronger base = ____ stable

3. strong acids are willing to lose protons because..

1. MOST

2. LEAST

3. they have a place to put the electrons that is stable

6.2

1. strong acids pka is..

2. moderately strong acids pka is..

3. weak acids pka is..

4. very weak acids pka is..

5. EXTREMLY weak acids pka is..

1. <1 (HCl, HBr, HI)

2. 1-3

3. 3-5

4. 5-15

5. >15 (H2O)

6.3 CARIOS

1. C=

2. A=

3. R=

4. I=

5. O=

6. S=

1. charge

2. atom

3. resonance

4. induction

5. orbital

6. solvation

6.3 CHARGE

positively changed acids are

protonated, H+

6.3 CHARGE

carbon tail

longer carbon tail less acidic

6.3 CHARGE

1. more acidic the molecule, ___ charge

2. more basic the molecule, ___ charge

1. +

2. -

6.3 ATOM

____ atoms are better for stabilizing negative charge

electronegative

6.3 ATOM

1. larger atoms ____ acidic

2. smaller atoms ____ acidic

1. more acidic, more room for e-

2. less acidic, less room for e-

(dif. in size more important that dif. in charge!!)

6.3 RESONANCE

resonance stabilizes the negative charge by…

spreading it out into partial charges

6.3 RESONANCE

more stable the conjugate base..

more likely the protons taken away

6.3 INDUCTION

induction stabilizes negative charge by..

spreading it out (like resonance)

6.3 INDUCTION

if there is a highly negative atom on the molecule undergoing protonation..

the negatively charged atom will share the negative charge through resonance and pull the charge towards itself, stabilizing the molecule

6.3 INDUCTION

induction causes the atom to be..

more acidic, induction = highly e- species in proximity to e-

(F, Br, Cl)

6.3 ORBITAL

negative charges need to be ___ to the nucleus because ___

closer, because it holds protons (positive charge)

6.3 ORBITAL

1. sp3

2. sp2

3. sp

1. least acidic (furthest away bc. least s character)

2. middle

3. most acidic (closest together bc. more s character)

6.3 SOLVATION

in simular atoms, branching causes …

the solvent to be blocked from the proton

6.3 SOLVATION

solution ___ the negative charge

stabilizes the …

stabilizes

transitions states, intermediate, and/ or products to allow reaction

6.4 what difference causes a non reversible protenation

difference in pka greater than 10

6.4 a stronger acid wants to what?

give away a proton

6.4 how to find the difference in amount of products vs. reactants

large pka-small pka= n 10^n is the difference

6.4 how to choose a strong reagent (base)

protonate the base (negative) so that the equilibrium will favor the products

6.4 how to protonate the base

choose an acid more acidic than the conjugate acid of the base, arrow right favors products = good reagent

6.4 how to choose a reagent (acid)

deprotenate the acid (positive) so that the equilibrium will favor the products

6.4 how to deprotenate the acid

choose a base with a conjugate acid more acidic than the original acid

6.4 a solvent should ___ react with itself

NOT, it is there to facilitate collisions of the acid and base

6.4 acids greater than ___ cannot exist in water

-1.74, H3O+ (conjugate base H2O), it will favor reactants not products

6.4 bases strong than ___ cannot be used in water

OH-, its conjugate acid is H2O

7.1

1. exergonic reaction

2. endergonic reaction

1. thermodynamically favored, reactants higher in energy than products, - delta H/G

2. unfavored, products higher in energy than reactants, + delta H/G

7.1

1. energy is delta ___

2. potential energy is delta ___

1. H

2. G

7.1

1. transition state is the

2. intermediate is the

1. humps, energy maxima, not observable

2. valleys, energy minima, oberservable

7.1

1. in an exergonic reaction, the transition state is closer to the

2. in an endergonic reaction, the transitions state is closer to the

1. reactants

2. products

7.1

1. small EA

2. larger EA

1. kinetically favored, fast

2. unfavored, slow

7.1 heterolytic

bond cleavage breaks and goes to one molecule, creates ions X—Y —> X+ + Y-

7.2 homolytic

bond cleavage breaks and separates to both evenly, creates radicals

X—Y —> X* + Y*

7.2 BDE

bond disassociation energy for homolytic bond cleavage

7.2 - delta H is

exothermic, bond energy gained > energy needed to break, temp of surroundings increases, stable products

7.2 + delta H is

endothermic, energy needed to break > bond energy gained, temp of surroundings decreases, unstable products

7.2 stronger bonds need __ energy to be broken

more

7.2