Kp

Question 1

What are mole fractions?

Answer 1

• the proportion by volume of gases to its total volume in a gas mixture

Question 2

How do you calculate mole fractions?

Answer 2

• number of moles / total number of moles

Question 3

what are the rules of mole fractions?

Answer 3

• mole fractions have no units
• the sum of all mole fractions is 1

Question 4

what is partial pressure?

Answer 4

• the individual pressures that each gas exerts in a gaseous mixture of gases

Question 5

what is the symbol of partial pressure?

Answer 5

P (X)

Question 6

what is total pressure?

Answer 6

• the sum of all partial pressures of individual gasses in a gas mixture

Question 7

How do you calculate partial pressures of a gas in a mixture?

Answer 7

mole fraction x total pressure

Question 8

what is all partial pressures equal to?

Answer 8

total pressure

Question 9

What are the units for Kp?

Answer 9

atm/pa

Question 10

How does Kp change with an exothermic reaction?

Answer 10

• if the forward reaction is exothermic
• if temperature increases, the equillibrium will shift to the left reaction, increasing the concentration of the reactants
• This increases the denominator of the kp expression and therefore decreases kp

Question 11

How does Kp change with an endothermic reaction?

Answer 11

• if the forward reaction is endothermic
• if temperature increases, equilibrium will shift to the right and increases the concentration of the products
• this will increase the numerator and will therefore increases kp

Question 12

What affects equilibrium constants?

Answer 12

• pressure and concentration does not affect the value of the equilibrium constant,K
• Catalysts do not affect the position of equilibrium
• instead equilibrium shifts in response to changes

Question 13

How does equillibrium shift when the concentration of reactants increases?

Answer 13

N2O4 = 2NO2
- if the concentration of N2O4 increases, the concentration of NO2 must increase and the concentration of N2O4 must decrease
- therefore equilibrium position will shift to the right

Question 14

How does equilibrium shift when the pressure of a reaction increases?

Answer 14

N2O4 = 2NO2
- if the pressure increases , the partial pressures increase
- to return to the normal kp ratio, the partial pressure of NO2 must decrease and the partial pressure of N2O4 must increase
- Therefore equilibrium position will shift to the left