1.45 pH

Question 1

what is a hydronium ion?

Answer 1

a hydrated proton

Question 2

what does the bronsted-lowry definition state about acids and bases?

Answer 2

acid - proton donor
base - proton acceptor

Question 3

water is -, meaning…

Answer 3

amphoteric, it can react as an acid or a base

Question 4

how is the dissociation of water (ionic product) represented?

Answer 4

Kw

Question 5

what is the value of Kw at room temperature?

Answer 5

1 x 10-14

Question 6

how does the value of the ionic product vary?

Answer 6

with temperature

Question 7

what is formed when an acid donates a proton?

Answer 7

A conjugate base

Question 8

what is formed when a base accepts a proton?

Answer 8

a conjugate acid

Question 8

what is formed when a base accepts a proton?

Answer 8

a conjugate acid

Question 9

how do strong acids/bases behave in solution?

Answer 9

completely dissociate into ions

Question 10

how do weak acids and bases behave in solution?

Answer 10

only partially dissociate into ions

Question 11

examples of strong acids?

Answer 11

hydrochloric, sulfuric, nitric

Question 12

which bases are strong?

Answer 12

solutions of metal hydroxides

Question 13

how do equimolar solutions of weak and strong acids/bases differ?

Answer 13

pH values, conductivity, reaction rates

Question 14

what is the same about equimolar solutions of strong and weak acids/bases?

Answer 14

stoichiometry of reactions

Question 15

how should the pH of a weak acid be calculated?

Answer 15

using pKa values

Question 16

soluble salt of strong acid strong base produces…

Answer 16

a neutral solution

Question 17

salt of weak acid strong base produces…

Answer 17

alkaline solution

Question 18

salt of strong acid weak base produces…

Answer 18

acidic solution

Question 19

how does strong acid/weak base affect the water equilibrium?

Answer 19

the weak base ion removes OH-, causing water equilibrium to shift right producing excess hydronium

Question 20

how does weak acid/strong base affect the water equilibrium?

Answer 20

the weak acid ion removes H30+, causing water equilibrium to shift right producing excess OH-

Question 21

how does strong acid/strong base affect the water equilibrium

Answer 21

neither ion has an impact so hydronium and Oh- concentrations remain equal

Question 22

what is a buffer solution?

Answer 22

one in which the pH remains approximately constant when small amounts of acid, base or water are added

Question 23

what does an acid buffer consist of?

Answer 23

a solution of a weak acid and one of its salts made from a strong base

Question 24

how does an acid buffer work?

Answer 24

- the weak acid provides hydrogen ions (when a small amount of base removes them) - the salt of the weak acid provides the conjugate base which absorbs excess hydrogen ions (when a small amount of acid adds them)

Question 25

what does a basic buffer consist of?

Answer 25

a solution of a weak base and one of its salts

Question 26

how does a basic buffer work?

Answer 26

the weak base removes excess hydrogen ions the conjugate acid provided by the salt supplies hydrogen ions when these are removed

Question 27

how is the acid indicator dissociation constant represented?

Answer 27

as Kin

Question 28

in solution the colour of a acid indicator is ... from that of its conjugate base

Answer 28

distinctly different

Question 29

what is the equivalence point?

Answer 29

the midpoint of rapid increase in pH

Question 30

which indicator would be suitable for strong acid/strong base?

Answer 30

one which changes colour around pH 7

Question 31

which indicator would be suitable for strong acid/weak base?

Answer 31

one which changes colour at an acidic pH

Question 32

which indicator would be suitable for weak acid/strong base?

Answer 32

one which changes colour at basic pH

Question 33

why is it not possible to select a suitable indicator for weak acid/weak base?

Answer 33

the pH does not change rapidly enough at the end point

Question 34

indicators are...

Answer 34

weak acids

Question 35

what is the colour of the indicator determined by?

Answer 35

the ratio of HIn to In-

Question 36

what is the theoretical point at which colour change occurs?

Answer 36

when H30+ = KIn

Question 37

when is the colour change of an indicator assumed to be distinguishable?

Answer 37

when HIn and In- differ by a factor of 10

Question 38

the pH range over which a colour change occurs can be estimated be the expression

Answer 38

pH = pKIn ± 1