In: Chemistry
#1. In the reaction: C2H4(g) + H2O(g) <---> C2H5OH(g) DeltaH = -47.8 kJ Kc = 9.00*103 @ 600. K
a. At equilibrium, PC2H5OH = 200. atm & PH2O = 400. atm. Calculate PC2H4.
b. Which set of conditions results in the highest yield of product.
Pressure high/low __________ Temperature high/low ________
Answer – We are given, reaction –
C2H4(g) + H2O(g) <---> C2H5OH(g) ∆H = -47.8 kJ Kc = 9.00*103 T= 600. K
At equilibrium, PC2H5OH = 200. atm & PH2O = 400. Atm
First we need to calculate the Kp form the Kc
Kp = Kc (RT)∆n
We know,
∆n = sum of the moles of the product – reactant
= 1 – 2 = -1
Kp = 9.00*103 *(0.0821 *600)-1
=182.7
Now we know
Kp = PH2O * PC2H4 / PC2H5OH
182.7 = 400.0 atm * PC2H4 /200.0 atm
182.7*200 = 400* PC2H4 /
36540 = 400* PC2H4
PC2H4 = 91.35 atm
b) We are given the negative enthalpy of reaction and we calculated the Kp of the reaction. We know when negative enthalpy then it is exothermic reaction, so as we increase the temp there is decrease the product. We also know when we increase the pressure the equilibrium will shift towards the fewer moles of side, so at the conditions pressure is high and temperature low gives highest yield of product.