jerwannaknow
contestada

This is the equation for the dissociation of ammonia gas at 293 K. H = 145 kJ and S = 195 J/k.

2NH3(g) N2(g) + 3H2(g)

Which correctly states the G for this dissociation and whether the process is spontaneous or nonspontaneous? Use G = H – TS.

Respuesta :

BlueSky06
We are given the equation for the dissociation of ammonia gas at 293 K. 

2NH3 (g) ==> N2(g) + 3H2(g)

and H = 145 kJ; S = 195 J/K

To determine the Gibb's Free Energy for this reaction, use the formula:

G = H - TS
substitute the given values:
G = 145x10^3 J - 293K * 195 J/K
G = 87865 Joules

The dissociation of ammonia gas has a positive Gibb's Free Energy, thus, the reaction is not spontaneous. Spontaneous reactions have Gibb's Free Energy which is less than zero or a negative number. 
irocktheworld11

The correct answer is 87.9 kJ, nonspontaneous