chapter 19

Question 1

what does it mean if Kc = 1?

Answer 1

position of E lies halfway between products and reactants

Question 2

what does it mean if Kc > 1?

Answer 2

position of E lies on the right
[products]>[reactants]

Question 2

what does it mean if Kc < 1?

Answer 2

position of E lies on the left
[reactants]>[products]

Question 3

what is homogenous equilibrium?

Answer 3

all species are in the same physical state

Question 4

what is heterogeneous equilibrium?

Answer 4

contains species of at least two different physical states
(leave out solids and liquids, only use aq and g)

Question 5

how do you calculate Kc?

Answer 5

initial moles
calculate change in moles using ratio
calculate equilibrium moles
divide by total moles to get molar fractions for pp or do n=cv
plug values into Kc equation

Question 6

how do you find the molar fraction x(A)?

Answer 6

total of moles A / total moles

Question 7

what is another formula for molar fraction x(A)?

Answer 7

volume of A / total volume

Question 8

what does x(A) + x(B)… =?

Answer 8

1

Question 9

what does the total partial pressure (P) equal?

Answer 9

partial pressure of A + partial pressure of B
p(A) + p(B)

Question 10

how do you calculate the partial pressure of a gas?

Answer 10

x(A) x P
molar fraction of gas x total partial pressure

Question 11

what does the Kp equation look like?

Answer 11

only gas species !!!!
curved not square brackets
(remember to calculate units)

Question 12

does Kc change if you change the concentration?

Answer 12

NO

Question 13

what happens if you increase the concentration of a substance in a Kc equation?

Answer 13

if substance is on numerator of Kc equation then expression will increase
expression now has value greater than Kc
to restore expression to Kc you must decrease numerator and increase denominator

Question 14

does Kp change if you change the partial pressure?

Answer 14

NO

Question 15

what happens if you increase the pressure of a gas in a Kp equation?

Answer 15

increasing pressure will increase partial pressure of both gases
if the numerator is squared/cubed (greater than indices on denominator) then numerator will increase more than denominator
to restore expression to Kp numerator value will have to decrease and denominator increase

Question 16

does change in temperature change Kc?

Answer 16

YES

Question 17

what happens if you increase the temperature of an endothermic reaction Kc expression?

Answer 17

when temperature increases Kp increases
expression now has a value less than Kp
to restore expression to new Kp value, numerator value will need to increase and denominator will need to decrease