The given balanced chemical equation is:
[C_2H_4(g) + H_2(g) \rightarrow C_2H_6(g)]
We need to write the expression for the equilibrium constant ((K_{\text{eq}})) for this reaction.
The equilibrium constant, \( K_{eq} \), for a reaction is the ratio of the concentrations of the products to the concentrations of the reactants, each raised to the power of their coefficient in the balanced chemical equation.
In this case, the balanced chemical equation is:
\[ C_2H_4(g) + H_2(g) \rightarrow C_2H_6(g) \]
The equilibrium constant expression would be:
\[ K_{eq} = \frac{[C_2H_6]}{[C_2H_4][H_2]} \]
Where:
- [C2H6] is the concentration of ethane (C2H6) at equilibrium
- [C2H4] is the concentration of ethene (C2H4) at equilibrium
- [H2] is the concentration of hydrogen (H2) at equilibrium
Note that the coefficients of the balanced chemical equation become the exponents in the equilibrium constant expression.