Question

What is the numerical value of Kc

for the following reaction if the equilibrium mixture contains 0.35 M
CO2
, 0.029 M
H2
, 0.24 M
CO
, and 0.30 M
H2O
?

CO2(g)+H2(g)⇌CO(g)+H2O(g)


Express your answer using two significant figures.

Answer 1

To find the numerical value of \(K_c\) for the given reaction, we can use the formula for the equilibrium constant expression:

\[K_c = \dfrac{[CO][H_2O]}{[CO_2][H_2]}\]

Given the concentrations at equilibrium:
\[ [CO_2] = 0.35 \, \text{M} \]
\[ [H_2] = 0.029 \, \text{M} \]
\[ [CO] = 0.24 \, \text{M} \]
\[ [H_2O] = 0.30 \, \text{M} \]

Now, plug in these values into the equilibrium constant expression:

\[ K_c = \dfrac{(0.24 \, \text{M})(0.30 \, \text{M})}{(0.35 \, \text{M})(0.029 \, \text{M})} \]

Calculate the value of \( K_c \):

\[ K_c = \dfrac{0.072 \, \text{M}^2}{0.01015 \, \text{M}^2} \]

\[ K_c \approx 7.08 \]

So, the numerical value of \( K_c \) for the given reaction, rounded to two significant figures, is approximately 7.08.