The given reaction is as follows:
2NO (g) + O₂ (g) = 2NO₂ (g), ΔH = -114 kJ
It is known that dSsurr = -dHsys / T (Temp = 355 K)
So, dSsurr = - (-114 × 1000) / 355
dSsurr = +321.12 J/K
Hence, the value of dSsurr is +321.12 J/K
For a reaction to be spontaneous, dG<0,
Also dStotal = dSsys + dSsurr > 0
It is known that dG = dHsys - TdSsys,
Now let us assume,
dG<0
Also, dStotal = dSsys + dSsurr > 0
(-114 × 1000) - (355 × dSsys) <0
355 × dSsys > -114 × 1000
dSsys > -321
dSsys >dSsurr
dSsys + dSsurr > 0
dStotal > 0
Thus, the assumption is correct, and the given reaction is spontaneous. Hence, the final answer is Ssurr = +321 J/K reaction is spontaneous.
