Chapter 10 Acids And Bases

Front 1

arrhenius acid

Back 1

species that dissociates in water to make H+ ions

Front 2

arrhenius base

Back 2

species that dissociates in water to make OH- ions

Front 3

arrhenius definition is limited to _____ solutions

Back 3

aqueous (H2O)

Front 4

bronsted-lowry acid

Back 4

donates protons/hydrogen atoms

Front 5

bronsted-lowry base

Back 5

accepts protons/hydrogen atoms

Front 6

bronsted-lowry definition is not limited to ____ solutions

Back 6

aqueous

Front 7

conjugate acid-base pairs

Back 7

common with bronsted-lowry definition

Front 8

conjugate acid

Back 8

acid that donates a proton in the forward rxn

Front 9

conjugate base

Back 9

base that gains a proton in the backward rxn

Front 10

ex) label conj acid/base in
H3O+ --> H+ + H2O

Back 10

H3O+ = acid
H2O = conjugate base

Front 11

Lewis acid

Back 11

electron pair acceptor

Front 12

lewis base

Back 12

electron pair donor

Front 13

lewis acids encompass all arrhenius and BL definitions, but not the other way around

Back 13

know this note

Front 14

lewis acids tend to show up as ____ in rxns

Back 14

catalysts

Front 15

nomenclature arrhenius acids
HF
HBr
HClO
HClO2
HClO3
HClO4

Back 15

hydrofluoric acid
hydrobromic acid
hypochlorous acid
chlorous acid
chloric acid
perchloric acid

Front 16

HNO2
HNO3

Back 16

Nitrous acid
Nitric acid

Front 17

water can act as both a ____ and an _____, making it _____

Back 17

base; acid; amphoteric

Front 18

water can react with itself through a process known as ____

Back 18

auto-ionization
H2O + H2O --> H3O+ OH-

Front 19

H3O+ =

Back 19

Hydronium ion

Front 20

water dissociation constant Kw =

Back 20

[OH-][H+] = 1e-14

Front 21

the value Kw changes only in reference to _____

Back 21

temperature

Front 22

at higher temperatures (other than 298K) the Kw value will be ____

Back 22

larger

Front 23

addition of H+ or OH- will only shift the equilibrium of the Kw equation, not change the Kw value itself!

Back 23

know this

Front 24

pH =

Back 24

-log[H+] or log[1/H+]

Front 25

pOH =

Back 25

-log[OH-] or log[1/OH-]

Front 26

pH + pOH =

Back 26

14

Front 27

pH less than 7 or pOH greater than 7 is _____

Back 27

acidic

Front 28

pH greater than 7 or a pOH less than 7 is ______

Back 28

basic

Front 29

pH of 7 =

Back 29

neutral

Front 30

estimating pH....
if given H+ = .00001 then....

Back 30

pH = -log[1e-5] = 5

Front 31

estimating less easy numbers...
given Ka = 1.8e-5....what is the pH?

Back 31

log[1.8e-5] = 5 - log[1.8] = pH is between 4 and 5

Front 32

log[fraction < 1] =

Back 32

negative

Front 33

log[fraction > 1]

Back 33

positive

Front 34

strong acids + bases ____ dissociate into their ionic components in aqueous solutions

Back 34

completely

Front 35

dissociation of strong acids and bases can be considered to go to ______

Back 35

completion

Front 36

strong acids commonly encountered include (6)

Back 36

HCl
HBr
H2SO4
HNO3
HI
HClO4

Front 37

strong bases commonly encountered include

Back 37

NaOH
KOH
OH- coupled with group I/II metal

Front 38

pH scale at 25C or 298 ranges from...

Back 38

1-14

Front 39

strength of acid dependent upon concentrations, not chemical behavior

Back 39

know

Front 40

weak acids and bases only _____ dissociate in aqueous solutions

Back 40

partially

Front 41

weak acid formula

Back 41

HA + H2O ---> H3O+ + A-

Front 42

acid dissociation constant Ka =

Back 42

[H+][A-] / [HA]

Front 43

the smaller the Ka value (closer to 1e-14) the _____ the acid

Back 43

weaker

Front 44

the smaller the Ka value, the ____ it will dissociate

Back 44

less

Front 45

weak base formula

Back 45

BOH ---> OH- + B+_

Front 46

the smaller the Kb value, the ____ the base

Back 46

weaker

Front 47

the smaller the Kb value, the ____ it will dissociate

Back 47

less

Front 48

if Ka is < 1 then...

Back 48

weak acid

Front 49

if Kb is < 1 then...

Back 49

weak base

Front 50

weak bases are almost always amines

Back 50

know

Front 51

conjugate acid

Back 51

the acid FORMED when a base gains a proton

Front 52

conjugate base

Back 52

the base FORMED when an acid loses a proton

Front 53

in a conjugate acid/base pair formed from a weak acid, the conjugate base is generally stronger than the conjugate acid

Back 53

know

Front 54

strong acid will produce a ____ conjugate base

Back 54

weak
HCl --> Cl-

Front 55

stong base will produce a ____ conjugate acid

Back 55

weak
NaOH --> H2O

Front 56

HCO3- + H2O --> CO3^2- + H3O+
find the conj acid/base of forward rxn

Back 56

CO3^2- = conjugate base
H3O+ = conjugate acid

Front 57

given: find H+ in a 2.0M solution of acetic acid CH3COOH with a Ka = 1.8e-5

EQ: CH3COOH --> H+ + CH3COO-

Back 57

Ka = [H+][CH3COO-] / [CH3COOH]

x^2 / 2 = 1.8e-5 ; --> x = 6e-3M

Front 58

salt/ neutralization formation

EQ =

Back 58

HA + BOH --> AB + H2O

Front 59

combinations of acids/bases
1. HCl + NaOH --> NaCl + H2O

2. HCl + NH3 --> NH4Cl

3. HClO + NaOH --> NaClO + H2O

4. HClO + NH3 --> NH4ClO

Back 59

SA + SB
SA + WB
WA + SB
WA + WB

Front 60

weak bases are not _____

Back 60

hydroxides

Front 61

product of SA + WB can react with water to form original weak base again

Back 61

know (pg 261)

Front 62

product of SB and WA can react with water to form original weak acid again

Back 62

know 262

Front 63

acid equivalent is ____

Back 63

1 mole of H+ ions
H2SO4 can create 2 equiv.

Front 64

base equivalent is _____

Back 64

1 mole of OH- ions
Ca(OH)2 can create 2 equiv.

Front 65

equivalent weight is the molecular mass / _____

Back 65

number of equivalents (n)

Front 66

amphoteric species

Back 66

-water
-hydroxides of Al, Zn, Pb, Cr
-species that can act as oxidizing or reducing agents
-

Front 67

titration

Back 67

procedure used to determine the molarity of a known reactant in a solution

Front 68

titrations involve reacting a known volume of solution of unknown concentration (called the ____) with a known volume of solution of known concentration (called the _____)

Back 68

titrand; titrant

Front 69

in acid-base titration, the equivalence point is reached when....

Back 69

the number of acid equivalents in solution = the number of base equivalents added....vise versa

Front 70

titration and neutralization problems can use the following EQ:
NV = NV

Back 70

N = normalities(concentrations)
V = volumes
volumes have to be in same units

Front 71

the equivalence point does not need to be at pH = ____

Back 71

7

Front 72

equivalence point can be measure in 2 ways....

Back 72

1. use an indicator
2. graphical method

Front 73

indicator and pH

Back 73

color changes when it reaches the END POINT; not the EQ. POINT

Front 74

indicators are weak organic acid/bases

Back 74

know

Front 75

indicators do ___ significantly alter the EQ. PT due to low concentrations

Back 75

NOT

Front 76

indicator must always be a ____ acid or ____ base than the acid/base titrated

Back 76

WEAKER; WEAKER

Front 77

the most useful combinations of acid-base titrations are....

Back 77

SA/SB
SA/WB
WA/SB
....

WA/WB are not usually accurate...lacks shape change indicating an EQ. PT
--more gradual change

Front 78

Strong Acid and Strong Base titration curve...draw it

Back 78

http://www.myoops.org/twocw/mit/NR/rdonlyres/Chemistry/5-111Fall-2005/F5E3B564-7D9C-4284-9FBB-5B9C224C4E5A/0/chp_titration.jpg

addition of acid or base at beginning has no significant change in the pH

once pH reaches ~ 7, EQ PT at 7, sharp increase until basic pH reached.

flat line since addition of base does not change pH

Front 79

SA/SB and EQ PT vs End Pt

Back 79

equivalence pt is lower than the end point

Front 80

the equivalence point for a SA/SB curve is ____ at pH 7 for monovalent species(valence of 1)

Back 80

ALWAYS
ex) HCl is monovalent

Front 81

Weak Acid and Strong Base titration curve...draw it

Back 81

http://www.chem.ubc.ca/courseware/pH/section14/ph2.jpg

addition of pH at beginning has effect on pH, increases until EQ pt above pH of 7 (since basic) then peters off with addition of base still having effect on pH

Front 82

the EQ. pt for a WA/SB is ____ greater than pH 7 and _____ in nature

Back 82

ALWAYS; basic

Front 83

the initial pH of a WA/SB is generally ____ in comparison to a SA/SB initial pH (pH = 2)

Back 83

higher (closer to pH 4)

Front 84

WA/SB produces a stronger/weaker conjugate base and a stronger/weaker conjugate acid

choose

Back 84

stronger; weaker

Front 85

Weak base and Strong acid titration curve...draw it

Back 85

http://image.tutorvista.com/content/ionic-equilibrium/titration-curve-weak-base-strong-acid.gif

the initial pH is in the basic range
initial addition of acid changes the pH quickly
the EQ. PT is in the acidic range (<7)
addition of more acid still affects pH after EQ PT

Front 86

Weak base and strong acid will produce a stronger/weaker conjugate acid and a stronger/weaker conjugate base

choose

Back 86

stronger; weaker

makes pH < 7

Front 87

the EQ. PT for a WB and SA is always/never pH < 7 and is acidic/basic in natue

Back 87

always; acidic

Front 88

polyvalent acids and bases

Back 88

are not monovalent in nature...thus have multiple EQ. PTs depending upon the number of equivalents released

Front 89

ex) Na2CO3 + HCl --> HCO3- + NaCl
-the initial predominant species would be CO3/HCO3
-as more acid added, the predominant species would be CO3/HCO3

Back 89

-CO3
-both

Front 90

1. Na2CO3 + HCl --> HCO3- + NaCl
2. NaHCO3- + HCL --> H2CO3 + NaCl
the flat part of the graph =

Back 90

EQ. Pt CO3- --> HCO3-

Front 91

2. NaHCO3- + HCL --> H2CO3 + NaCl

- after the EQ. PT, the predominant species are HCO3-/H2CO3

Back 91

both in equal numbers

Front 92

2. NaHCO3- + HCL --> H2CO3 + NaCl

the second flat region, the predominant species is HCO3-/H2CO3

Back 92

H2CO3 = all HCO3- converted to this

Front 93

2. NaHCO3- + HCL --> H2CO3 + NaCl

the second large change in pH is

Back 93

the 2nd EQ. PT

Front 94

the titrations of the acidic and basic amino acids will have 2/3 EQ. pts

Back 94

3
1 = titration of the COOH
2 = titration of amino acid
3 = acidic/basic side chain

Front 95

buffer solution

Back 95

mixture of a weak acid and its salts(conjugate base + cation)

or

mixture of weak base and its salts(conjugate acid and anion)

Front 96

example of Acidic buffer

Back 96

CH3COOH + (Na+ + CH3COO-)

Front 97

basic buffer solution example

Back 97

NH3 + (NH4+ + Cl-)

Front 98

buffer solutions are capable of _____ changes in pH when small amts of acid/base are added

Back 98

resisting

Front 99

process of acidic buffer solution and NaOH addition

CH3COOH + H2O --> H3O+ + CH3COO-

Back 99

addition of NaOH --> Na+ and OH-
the OH- reacts with H+ to form H2O --> leads to shift in right to dissociate CH3COOH to form acid H3O+

Front 100

scenario with acidic buffer and HCl

CH3COOH + H2O --> H3O+ + CH3COO-

Back 100

the HCl --> H+ + Cl-
H+ reacts with CH3COO- to form CH3COOH (weaker acid) maintaining the pH
-shifts EQ to the left

Front 101

HCO3-/H2CO3 buffer most important with ____

Back 101

blood

Front 102

metabolic acidosis will cause the respiratory rate to increase/decrease and increase/decrease expulsion of CO2/H+ and will increase/decrease the pH

Back 102

increase
increase
increase

Front 103

blood pH is ....

Back 103

7.4

Front 104

henderson-hasselbach EQ

pH = pKa + log[conj. base]/[weak acid]

Back 104

know

Front 105

henderson-hasselbach EQ

pOH = pKb + log[conj. acid]/[weak base]

Back 105

know

Front 106

note: when [conj. base] = [weak acid], pH = pKa

note: when [conj. acid] = [weak base], pOH = pKb

Back 106

know

Front 107

if the ratio of the buffer components (1:1 --> 2:2) doesn't change, the pH of the buffer solution does not change....but what does change?

Back 107

buffering capacity
doubling the concentrations doubles the buffering capacity