Question

Earth's atmosphere is composed primarily of nitrogen and oxygen, which coexist at 25°C without
reacting to any significant extent. However, the two gases can react to form nitrogen monoxide
according to the following reaction: N,(g) + 0, (g) - 2 NO (g)
(a) Calculate AG° and K for this reaction at 25°C.
(b) Is the reaction spontaneous at 25°C?

Answer 1

Answer:

The ΔG° is 171,144.6 J/mol.

The reaction is not spontaneous.

Explanation:

Given values:

T=25°C (298K)

Kp at 25°C= 1x10^-30

To calculate the ΔG° it is necessary to replace the value of R (8.314J/mol.K), temperature and Kp:

$\begin{gathered} \Delta G°=-R*T*\ln(K_p) \\ \Delta G°=-8.314\frac{J}{mol.K}*298K*\ln(1*10^{-30}) \\ \Delta G°=171,144.6J/mol \end{gathered}$

So, the ΔG° is 171,144.6 J/mol. Since ΔG° is greater than 0, the reaction is not spontaneous.