Question

For the gas phase reaction,
$C_2{H}_4\left(g\right)+H_2\left(g\right)\rightleftharpoons C_2{H}_6\left(g\right);△H^o=-136.8kJmo{l}^{-1}$
carried out in a vessel, the equilibrium concentration of $C_2{H}_4$ can be increased by:

• A. Increasing the temperature
• B. Decreasing the pressure
• C. Removing some $H_2$
• D. Adding some $C_2{H}_6$

Answer 1

Answer: (A), (B), (C), (D)

Adding some $C_2{H}_6$

a. As the reaction is exothermic, the temperature reaction will shift in a backward direction, i.e., concentration of $C_2{H}_4$ will increase.

b. The reaction is carried out in the gas phase, hence on decreasing the pressure the reaction will shift in the direction where there are more number of moles.
Hence, reaction will shift on the reactant's side.

c. Removing the reactant, $H_2$ will shift the equilibrium to the backward direction and hence concentration of $C_2{H}_4$ will increase.

d. Adding the product $C_2{H}_6$ will shift the equilibrium to the backward direction and hence concentration of $C_2{H}_4$ will increase.