Part #1: Ammonia can be formed from hydrogen and nitrogen gases according to the
ID: 940797 • Letter: P
Question
Part #1:
Ammonia can be formed from hydrogen and nitrogen gases according to the following reaction:
3H2(g) + N2(g) --> 2NH3(g)
Alternatively, a mole of ammonia can be broken up into hydrogen and nitrogen gases according to the following formula:
NH3(g) --> 3/2 H2(g) + 1/2 N2(g)
Part #2:
Which transformations of the equilibrium constant K would you do from the first to the second reaction in part 1?
Part #3:
At a particular temperature, the equilibrium constant K of the first reaction in part 1 is equal to 7.34. What would the equilibrium constant be for the second reaction in part one?
Part #4:
If the Kc for the first reaction in part one is 7.34, calculate Kp for this reaction. Note, the temperature of this reaction is 292.2 K. (hint: if the pressures of the equilibrium constant Kp should be in atmospheres, what value of R should you use?)
Explanation / Answer
1)
Ka1 = [NH3]^2/[H2]^3[N2]
if you need
Ka2 = [H2]^3[N2]/[NH3]^2
then we must invert it
that is
Ka2 = 1/Ka1
3)
K1 = 7.34
then; for reaction 2
K2 = 1/K1 = 1/7.34 = 0.1362397
4)
You can relate Kp and Kc as follows
Kp = Kc*(RT)^dn
dn = moles of products - moles of reactant
dn = 2-(3+1) = -2
R = 0.082 atmL/molK
T = 292.2 K
then
Kp = Kc*(RT)^dn
Kp = 7.34*(0.082*292.2)^(-2)
Kp = 0.01278521194