chapter 16: acid-base equilibria

Question 1

what is H+ often called?

Answer 1

a proton

Question 2

definition of an acid

Answer 2

forms H+ ions in solution

Question 3

definition of a base

Answer 3

forms OH- ions in solution

Question 4

what is an Arrhenius acid?

Answer 4

a substance that, when dissolved in water, increases the concentration of hydronium ion, H3O+ ions.

Question 5

in real life, H+ (aq) does not exist and is a shorthand representation of what?

Answer 5

H3O+ (aq)

Question 6

what is an Arrhenius base?

Answer 6

a substance that, when dissolved in water, increases the concentration of hydroxide, OH- ions

Question 7

what is a Bronsted-Lowry acid?

Answer 7

a substance that donates a H+

Question 8

what is a Lewis acid?

Answer 8

a substance that accepts electrons

Question 8

what is a Bronsted-Lowry base?

Answer 8

a substance that combines with or accepts H+

Question 9

what is a Lewis base?

Answer 9

a substance that donates electrons

Question 10

what is an amphiprotic substance?

Answer 10

type of amphoteric substance that can both donate and accept protons (H⁺)

Question 11

what is self-ionization of water?

Answer 11

water spontaneously splitting into a conjugate acid and conjugate base, H3O+ and OH- in a equilibrium reaction

Question 12

pH =

Answer 12

-log [H3O+]

Question 13

what does pH literally mean?

Answer 13

potentia hydrogenii, the power of hydrogen

Question 14

pH lower than 7 indicates

Answer 14

acidic solution

Question 15

pH at 7 indicates

Answer 15

neutral solution

Question 16

pH higher than 7 indicates

Answer 16

basic solution (alkaline)

Question 17

pOH =

Answer 17

-log [OH-]

Question 18

strong acids have very…

Answer 18

weak conjugate bases

Question 19

weak acids have…

Answer 19

stronger conjugate bases (usually not as strong as OH-)

Question 20

what does amphoteric mean?

Answer 20

the ability to act as an acid or base

Question 21

Ka =

Answer 21

acid disassociation constant

Question 22

the larger the Ka value…

Answer 22

the more H+ is being produced

Question 23

pKa =

Answer 23

-log [Ka]

Question 24

the lower the pKa value...

Answer 24

the stronger the acid

Question 25

a strong acid...

Answer 25

completely transfers its protons to water, no undisassociated molecules in solutions

Question 26

a weak acid...

Answer 26

only partially disassociates in aqueous solution and exists in solution as a mix of acid and conjugate base

Question 27

what is acid strength or weakness defined by?

Answer 27

conjugate base

Question 28

what are some common strong acids?

Answer 28

HCl, HBr, HI, H2SO4, HNO3, HCLO4

Question 29

in general, Ka>

Answer 29

1 for a strong acid

Question 30

hydrohalic acids

Answer 30

acids made up of hydrogen and grp 17 halogens, strong acids in aqueous solutions, except HF

Question 31

why is HF is a weak acid?

Answer 31

small fluoride ion has a concentrated negative charge, attracting H+ cation and not allowing it to disassociate

Question 32

oxyacids

Answer 32

acids in which the central atom (usually N, Cl, S, or P) is bonded to at least one O2 atoms.

Question 33

the more oxygens present...

Answer 33

the stronger the acid (if central atom is same)

Question 34

for the same # of oxygens, the more electronegative the central atom...

Answer 34

the stronger the acid (pull toward central atom and away from O2, easier disassociation)

Question 35

the higher the negative charge on the anion...

Answer 35

the lower the acidity of the acid

Question 36

the more electronegative atoms present...

Answer 36

the higher the acidity of that acid

Question 37

Kb =

Answer 37

Kw/Ka

Question 38

Ka =

Answer 38

Kw/Kb

Question 39

pKw =

Answer 39

pKa + pKb

Question 40

Kw =

Answer 40

Ka times Kb

Question 41

how do you know if a salt is neutral?

Answer 41

salts made of BOTH conjugate bases of strong acids (anions) and conjugate acids of strong bases (cations) are neutral. NaB4, Ba(NO3)2, LiClO3.

Question 42

neutral cations

Answer 42

Li+, Na+, K+, Rb+, Cs+

Question 43

neutral anions

Answer 43

Cl-, Br-, I-, NO3-, SO42-, ClO4-

Question 44

what does percent ionization measure?

Answer 44

the relationship between the ionized product versus what was already there

Question 45

percent ionization formula

Answer 45

([H3O] equilibrium / [HA] initial) times 100

Question 46

percent ionization increases as...

Answer 46

acid strength increases