5.1.1

Question 1

In Arrheinus’s equation what effect does Ea have on the rate constant?

Answer 1

higher Ea
lower K value

Question 2

What effect does temperature have on the rate constant in Arrheinus’s equation?

Answer 2

higher temp

larger K value

Question 3

What condition is Kc dependent?

Answer 3

temp

Question 4

If the backwards temperature is endothermic, what happens to Kc when temp inc?

Answer 4

Kc dec

Question 5

What happens to KC when temperature dec if the backwards reaction is endothermic?

Answer 5

Kc inc

Question 6

What state symbol is allowed in the Kc equation?

Answer 6

aq

Question 7

2NO + O2 = 2NO2

What effect does a decreased pressure have?

Answer 7

lower conc of everything
denominator dec more than top so system no longer in eq
eq shifts to left
NO2 dissociates more to restore Kc
conc of reactants inc and products dec
until eq is restored

Question 8

N2O4 = 2NO2

What effect does pressure have?

Answer 8

inc in pressure inc conc of everything
numerator in Kc exp inc more than denominator and system no longer in eq
eq shifts to left
NO2 dissociates more to restore Kc
reactants inc products dec

Question 9

H2 + I2 = 2HI
What effect does temperature have?

Answer 9

inc in pressure inc conc of everything
both terms in Kc affected
Kc not changed so eq doesnt shift
eq stays the same

Question 10

What are acids?

Answer 10

proton donors

Question 11

What are bases?

Answer 11

proton acceptors

Question 12

What is the different dissociations in strong acids and weak acids?

Answer 12

strong acids fully dissociate
weak acids partially dissociate

Question 13

What is acid strength determined by?

Answer 13

H+ conc

Question 14

What is the difference between dissociations in strong and weak bases?

Answer 14

strong base fully dissociates
high OH- conc

weak base partially dissociates
low OH - conc

Question 15

The larger the value of Ka?

Answer 15

the greater the dissociation

Question 16

What is a buffer solution?

Answer 16

resists changes in pH when small amounts of acid / alkali are added

Question 17

What do acidic buffers do?

Answer 17

maintain pH lower than 7

Question 18

What do basic buffers do?

Answer 18

maintain pH higher than 7

Question 19

How do you make an acidic buffer?

Answer 19

weak acid and it’s salt conjugate base

Question 20

How do you make a basic buffer?

Answer 20

weak base and its salt conjugate acid

Question 21

What happens when you add acid to a buffer?

CH3COOH = CH3COO- +H+

Answer 21

H+ react with CH3COO- and equilibrium shifts left

Question 22

What happens when you add acid to a buffer?

CH3COOH = CH3COO- +H+

Answer 22

lowers H+ concentration so CH3COOH dissociates to replace them

equilibrium shifts to the right

Question 23

Where is the equivalence point?

Answer 23

centre of the verticla section

Question 24

What is the equivalence point?

Answer 24

equivalent number of moles of each chemical required by the mole ratio in the equation

Question 25

What happens in the initial section of a strong acid- strong base graph?

Answer 25

acid is in large excess addition of 1/2cm3 of NaOH doesnt change the pH that much

Question 26

How do you find the pH at equivalence?

Answer 26

centre of vertical section is pH

Question 26

Where will the vertical line be on a strong acid strong base graph?

Answer 26

25cm3

Question 26

What does the final section of a strong acid - strong base graph look like?

Answer 26

levels off at max pH

Question 27

Why is the pH at equivalence 7 for a strong acid - strong base graph?

Answer 27

neutral substances formed

Question 27

Why would the pH at equivalence be below 7 for strong acid weak base likee ammonia and hcl?

Answer 27

Ammonium chloride dissociates into ammonium ions and chloride ios Ammonium ions donate a proton making the pH slightly acidic

Question 28

Why is the pH at equivalence for weak acid strong base higher than 7?

Answer 28

the CH3COO- ions accept H+ from water to form ethanoic acid so it acts as a base

Question 29

Where will the graph for weak acid weak base start?

Answer 29

pH 3

Question 30

Where will the graph for weak acid weak base end?

Answer 30

pH 10

Question 31

Why is the pH at equivalence 7 for weak acid weak base? ethanoic acid and ammonium hydroxide

Answer 31

ethanoate ion = weak base ammonium ion = weak acid weak bases accept a H+ and weak acids donate a proton so they cancel eachover out so pH is 7

Question 32

What section must indicators fall in?

Answer 32

VERTICAL REGION

Question 33

What does a lower pKa mean?

Answer 33

stronger acid

Question 34

What is the only condition to affect K?

Answer 34

temp

Question 35

The larger K

Answer 35

the higher the rate of the reaction

Question 36

The higher the Kc?

Answer 36

the futher the equilibrium lies to the right

Question 37

What is the only factor to affect Kc?

Answer 37

temp

Question 38

The higher the Kp<

Answer 38

the futher the equilibrium lies to the right

Question 39

What does a higher Ka value mean?

Answer 39

more dissociated the weak acid is

Question 40

What is the only condition to affect rate constant?

Answer 40

temp

Question 41

What does a larger K value mean?

Answer 41

higher rate

Question 42

What happens to balancing numbers in the Kc?

Answer 42

become powers

Question 43

What does a higher Kc indicate?

Answer 43

equilibrium lies fither to the rightWhat

Question 44

What is the only condition to affect Kc?

Answer 44

temop

Question 45

What does c represent in Kc?

Answer 45

equilibrium concentrations

Question 46

Whatmethod is sued to calc concentrations in Kc?

Answer 46

ICE

Question 47

What does a higher Kp indicate?

Answer 47

eq lies futher to the right

Question 48

What is the only condition to affect Kp?

Answer 48

temp

Question 49

what does p represent in Kp?

Answer 49

partial pressures of gas components

Question 50

What is thr equation for partial pressure?

Answer 50

mole fraction X total pressure

Question 51

What is Ka used to calculate?

Answer 51

pH of weak monobasic acids

Question 52

What does a higher Ka indicate?

Answer 52

more dissociated the weak acid

Question 53

What does a lower pKa indicate?

Answer 53

more weak acid is dissociated

Question 54

What is the ionic product of water used to calculate?

Answer 54

pH of strong alkalis where we know [OH-]