(BLUE) Equilibria II - Kp

Question 1

What is the definition of partial pressure

Answer 1

pA is a mixture of gases is the pressure that the gas A would exert if it were alone in the container at that particular temperature

Question 2

What is the equation for partial pressure

Answer 2

Partial pressure = molar fraction x total pressure

Question 3

What is the equation for molar fraction

Answer 3

Molar fraction = moles of A / total number of moles of gas

Question 4

What is the equation for Kp

Answer 4

Kp= partial pressure of products timesed together/ partial pressure of reactants timesed together

Question 5

Solve :
1 mole of ammonia
3.6 moles of hydrogen
1 mole of nitrogen
At 2atm
Find Kp

Answer 5

Find molar fraction
Moles of compound divided by the total moles

Then

Find partial pressure
Molar fraction x 2atm (pressure)

Insert into Kp equation giving :0.1289

Question 6

What does it mean if (delta) Stotal is positive

Answer 6

It means that it is spontaneous

Question 7

What does it mean if (delta) G is negative

Answer 7

That the reaction is feasible

Question 8

Give the equation for (DELTA) S total

Answer 8

= R x ln(K)

R is 8.31
K is constant

Question 9

Give the equation for (delta) G

Answer 9

= -RT x ln(k)

Question 10

Hard : explain how in and exothermic reaction increasing Tempreature moves the eqm to the left

Answer 10

Ln(k) = - ( - delta H / RT) + delta sys/R

As we increase T , we decrease lnk ,this therefore moves the eqm to the left

Question 11

Hard : explain how in and endothermic reaction increasing Tempreature moves the eqm to the right

Answer 11

Ln(k) = - ( + delta H / RT) + delta sys/R

As we increase T , we increase lnk ,this therefore moves the eqm to the right

Question 12

If K is low eg 9.5x10^-8 what does this mean

Answer 12

Almost no reactants have reacted as delta G is positive

Question 13

If K is high eg 1000000 what does this mean

Answer 13

Almost all reactants have reacted , delta G is negative

Question 14

Why are solids not involved in Kp equations

Answer 14

As they have negligible pressure

Question 15

Explain by reference to any changes in the value of Kp the effect of an increase in temperature on the equilibrium position of this reaction

Answer 15

An increase in temperature will increase the value of Kp as the forward reaction is endothermic , and therefore more co2 and H2 will form as a result , increasing there partial pressure as molar fraction increases , while decreasing the partial pressure of H2O

Question 16

What happens if Kc /Kp = 1

Answer 16

Both reactants and products equal each other