Question

Acetylene, C2H2, can be converted to ethane, C2H6, by a process known as hydrogenation. The reaction is C2H2(g)+2H2(g)⇌C2H6(g) Given the following data at standard conditions (all pressures equal to 1 atm and the common reference temperature 298 K), what is the value of Kp for this reaction?

Answer 1

Answer:

K = Kp =  2.7 *10^42

Explanation:

Step 1: Data given

All pressure are equal to 1.0 atm

Temperature = 298 K

Delta Gf Values (kJ/mol):

C2H2(g) 209.2  kJ/mol

H2(g) 0  kJ/mol

C2H6(g) -32.89 kJ/mol

Step 2: The balanced equation

C2H2(g) + 2H2(g) <----> C2H6(g)

Step 3: Calculate K

ΔGf for this reaction is:

Delta Gf = (1)(209.2) - (1)(-32.89) - (2)(0) = 242.09 kJ/mol

ΔGf  for reaction = sum of moles of each product * ΔGf  of each product, minus the sum of moles of each reactant * ΔGf  of each reactant using the number of moles from the balanced chemical reaction

ΔGf  for reaction = - RT lnK

ΔGf = -242.09 kJ/mol

ΔGf = -242090 J/mol

-242090 kJ/ mol = -RT lnK = -(8.314)*(298) * lnK

K = Kp =  2.7 *10^42