Question

Ethylene can be converted to ethanol according to the following reaction:

C2H4(g) + H2O(g) ⇌ CH3CH2OH(l)

The reaction is catalyzed by H+(aq).

You will use the following table for this problem:

Substance:    ΔGf (kJ/mol)

C2H4(g)    74.2

H2O(g)     -231.9

CH3CH2OH(l) -177.8

Part 1:

What is ΔGo of this reaction in kJ/mol?

Part 2:

What is the value of K for this reaction given your value of ΔGo in part 1 at 25oC?

Answer 1

1)

we have:

Gof(C2H4(g)) = 74.2 KJ/mol

Gof(H2O(g)) = -231.9 KJ/mol

Gof(CH3CH2OH(l)) = -177.8 KJ/mol

we have the Balanced chemical equation as:

C2H4(g) + H2O(g) ---> CH3CH2OH(l)

deltaGo rxn = 1*Gof(CH3CH2OH(l)) - 1*Gof( C2H4(g)) - 1*Gof(H2O(g))

deltaGo rxn = 1*(-177.8) - 1*(74.2) - 1*(-231.9)

deltaGo rxn = -20.1 KJ/mol

Answer: -20.1 KJ/mol

2)

T= 25.0 oC

= (25.0+273) K

= 298 K

deltaG = -20.1 KJ/mol

deltaG = -20100 J/mol

we have below equation to be used:

deltaG = -R*T*ln Kc

-20100 = - 8.314*298.0* ln(Kc)

ln Kc = 8.1128

Kc = 3.34*10^3

Answer: 3.34*10^3

Feel free to comment below if you have any doubts or if this answer do not work. I will correct it and submit again if you let me know