Ch 10: Acids and Bases

Question 1

Arrhenius acids

Answer 1

dissociate to produce excess hydrogen ions in soln

Question 2

Arrhenius bases

Answer 2

dissociate to produce excess hydroxide ions in soln

Question 3

Bronsted-Lowry acids

Answer 3

species that can donate hydrogen ions

Question 4

Bronsted-Lowry bases

Answer 4

electron-pair donors

Question 5

all ____ are Bronsted-Lowry acids and bases, and all Bronsted-Lowry acids and bases are ____ but the reverse of this is not true

Answer 5

Arrhenius acids and bases

Lewis acids and bases

Question 6

Lewis acids are

Answer 6

electron-pair acceptors

Question 7

Lewis bases are

Answer 7

electron-pair donors

Question 8

amphoteric

Answer 8

behave as acid or base

Question 9

amphiprotic species are

Answer 9

amphoteric species that specifically can behave as Bronsted-Lowry acids and bases

ex: water

Question 10

conjugate species of polyvalent acids and bases can behave as

Answer 10

amphoteric and amphiprotic species

Question 11

water dissociation constant, Kw

Answer 11

10^-14 at 298K

like other equilibrium constants, only affected by temperature

Question 12

pH and pOH =

Answer 12

14 at 298K

Question 13

strong acids and bases

Answer 13

complete dissociate

Question 14

weak acids and bases

Answer 14

do not completely dissociate and have dissociation constants (Ka and Kb)

Question 15

Neutralization reactions

Answer 15

form salts and sometimes water

Question 16

equivalent is defined as

Answer 16

one mole of the species of interest

Question 17

in acid-base chemistry, normality is

Answer 17

the concentration of acid or base equivalents in solution

Question 18

polyvalent acids and bases

Answer 18

those that can donate or accept multiple electrons. The normality of a solution containing a polyvalent species is the molarity of the acid or base times the number of protons it can donate or accept

Question 19

titrations

Answer 19

used to determine the concentration of a known reactant in the solution

Question 20

titrant

Answer 20

known concentration and is added slowly to the titrand to reach the equivalence point

Question 21

titrand

Answer 21

unknown concentration but a known volume

Question 22

half-equivalence point

Answer 22

midpoint of the buffering region, which half of the titrant has been protonated (or deprotonated); thus [HA] = [A-] and a buffer is formed

Question 23

equivalence point

Answer 23

indicated by the steepest slope in a titration curve; it is reached when the number of acid equivalents in the original solution equals the number of base equivalents added, or vice-versa

Question 24

strong acid and strong base titrations have equivalence points at

Answer 24

pH = 7

Question 25

weak acid and strong base titrations have equivalence points at

Answer 25

ph > 7

Question 26

strong acid and weak base titrations have equivalence points at

Answer 26

ph

Question 27

weak acid and weak base titrations can have equivalence points

Answer 27

above or below 7, depending on the relative strength of the acid or base

Question 28

indicators are

Answer 28

weak acids or bases that display different colors in their protonated and deprotonated forms

indicator chosen for a titration should have a pKa close to the pH of the expected equivalency point

Question 29

endpoint of a titration

Answer 29

is when the indicator reaches its final color

Question 30

multiple buffering regions and equivalence points are

Answer 30

observed in polyvalent acid and base titrations

Question 31

buffer solutions

Answer 31

consist of a mixture of a weak acid and its conjugate salt or a weak base and its conjugate salt; they resist large fluctuations in pH

Question 32

buffering capacity

Answer 32

refers to the ability of a buffer to resist changes in pH; maximizing buffering capacity is seen within 1 pH point of the pKa of the acid in the buffer solution

Question 33

Henderson-Hasselbach equation

Answer 33

quantifies the relationship between pH and pKa for weak acids and between pOH and pKb for weak bases; when a solution is optimally buffered pH = pKa and pOH = pKb