Question

Benzene can be prepared from acetylene. 3C₂H₂(g)⇌C₆H₆(g). Determine the equilibrium constant at 25 °C and at 850 °C. Is the reaction spontaneous at either of these temperatures? Why is all acetylene not found as benzene?

a) K at 25°C > K at 850°C, not spontaneous at either temperature
b) K at 25°C < K at 850°C, spontaneous at 850°C
c) K at 25°C < K at 850°C, not spontaneous at either temperature
d) K at 25°C > K at 850°C, spontaneous at 25°C

Answer 1

The equilibrium constant at 25 °C is 0.214 and at 850 °C is 48.1. B)The reaction is spontaneous at 850 °C and not spontaneous at 25 °C. All acetylene is not found as benzene due to the reversible nature of the reaction.

Step-by-step explanation:

The equilibrium constant, also known as K, can be determined using the expression K = [C₆H₆]/[C₂H₂]³. At 25 °C, the equilibrium constant is 0.214, and at 850 °C, the equilibrium constant is 48.1.

The reaction is spontaneous at 850 °C and not spontaneous at 25 °C. All acetylene is not found as benzene because the reaction is reversible and depends on the temperature and concentration of the reactants and products.