CHM 142 Exam 2

Question 1

Are pure solids and pure liquids written into Keq equations?

Answer 1

No, they have a value of 1 because their activity is 1

they have constant concentration

Question 2

Reactant Quotient

Answer 2

similar to Keq but concentrations used can be from any point in the reaction

Question 3

Q»K

Answer 3

reaction proceeds left, forming more reactants

right to left

Question 4

Q«K

Answer 4

reaction proceeds right, forming more products

left to right

Question 5

Q= K

Answer 5

reaction must be at equilibrium

Question 6

Which way does the reaction proceed if the volume is decreased and pressure is increased?

Answer 6

the reaction will shift in the direction of less moles

Question 7

which way does the reaction proceed if the pressure is decreased and the volume is increased?

Answer 7

The reaction will shift to the side that produces more moles

Question 8

For an exothermic reaction (H is -) that has heat taken from the system, which way does it proceed?

Answer 8

exothermic = reactants— products + heat so the reaction moves right

increases K

Question 9

For an endothermic reaction (H +) that has heat added to the system, which way does it proceed?

Answer 9

endothermic = reactants + heat—products so the reaction shifts to the right

Increases K

Question 10

How does a catalyst affect equilibrium?

Answer 10

it does not affect Keq but it does get the reaction to meet eq faster than without it

Question 11

Arrhenius Acid

Answer 11

Increases the concentration of H+ ions

Question 12

Arrhenius Base

Answer 12

Increases the concentration of OH- ions

Question 13

Bronsted-Lowry acid

Answer 13

proton donor

Question 14

Bronsted Lowry base

Answer 14

proton acceptor

Question 15

a substance that can be both an acid and a base with the right electron configuration and # of H+ ions

Answer 15

Amphiprotic

Question 16

Conjugate base

Answer 16

-1 H+ from an acid

Question 17

Conjugate acid

Answer 17

+1 H from a base

Question 18

the stronger the acid the —- its conjugate base

Answer 18

weaker

Question 19

the stronger the base the—its conjugate acid

Answer 19

weaker

Question 20

In acid-base rxns what will eq favor?

Answer 20

the transfer of the proton from the stronger acid to the stronger base to form a weaker acid and weaker base

Question 21

when water donates protons to other water molecules

Answer 21

Autoionization

Question 22

Kw, Ion product constant

Answer 22

the eq constant for ionization of water

1.*10^-14

Question 23

what kind of solution is it when [H+]>[OH-]

Answer 23

acidic

Question 24

what kind of solution is it when [H+]<[OH-]

Answer 24

basic

Question 25

pH=

Answer 25

-log[H+]

Question 26

pOH=

Answer 26

-log[OH-]

Question 27

14.00=

Answer 27

pH+pOH

Question 28

true or false? everytime you move up a unit on the pH scale the [H+] increases *10

Answer 28

false, everytime you move down a unit on the pH the concentration increases *10

Question 29

a strong electrolyte that completely dissociates into H+ ions

Answer 29

strong acid

Question 30

a strong electrolyte that completely dissociates into OH- ions

Answer 30

strong base

Question 31

for strong monoprotic acids [H+]=

Answer 31

[base]

Question 32

for diprotic strong bases [OH]

Answer 32

= 2*[base]

Question 33

weak electrolytes that only partially dissociate into H+

Answer 33

weak acids

Question 34

what do weak acids do that strong acids dont?

Answer 34

they establish equilibrium

Question 35

the --- the values of Ka the --- the acid

Answer 35

larger, stronger

Question 36

[H+]= | strong acid

Answer 36

[acid]

Question 37

[H+]< | weak acid

Answer 37

[acid] initial

Question 38

percent ionization for HA

Answer 38

[H+]eq/[HA]eq *100

Question 39

ionization equation for weak acids

Answer 39

HA (aq)---[H3O+]+[A-]

Question 40

weak bases

Answer 40

partially dissociate into OH- ions + a conjugate acid in water

Question 41

Kb=

Answer 41

[CA+][OH-]/[B]

Question 42

What are the two types of weak bases?

Answer 42

1. neutral substances that have a nb pair of electrons to accept the proton (typically have a N atom) 2. anions that are conjugate bases of a weak acid

Question 43

[Ka]*[Kb]=

Answer 43

1.0*10^-14

Question 44

pKa+pKb=

Answer 44

14.00

Question 45

Cations can be --- and ----

Answer 45

acidic and neutral

Question 46

Anions can be ---,--- and ---

Answer 46

acidic, basic, and neutral

Question 47

are anions from a strong acid neutral, basic or acidic

Answer 47

neutral

Question 48

are anions from a weak acids basic, acidic or neutral

Answer 48

basic

Question 49

are anions from a polyprotic acid bases, acids or neutral

Answer 49

they can be both | compare Ka and Kb

Question 50

are cations from strong bases acidic or neutral | grp I and grp II cations

Answer 50

neutral

Question 51

are conjugate acids from weak bases acidic or neutral

Answer 51

acidic

Question 52

are transition and post transition metal cations acidic or neutral

Answer 52

acidic

Question 53

neutral ion + basic ion=

Answer 53

basic solution

Question 54

basic ion+ acidic ion=

Answer 54

compare Ka and Kb values | the larger values determines pH level