Answer in General Chemistry for Sheena #156393

A reaction has ΔH° = 100 kJ/mol and ΔS°=250 J/mol.K. Is the reaction spontaneous at room temperature? If not, under what temperature conditions will it become spontaneous?

“Delta”H⁰ = 100KJ/mol and “Delta”S⁰ = 250J/mol.K

Room temperature = 298K

“Delta” G⁰ = “Delta” H⁰ – T “Delta” S⁰

= 100 KJ/mol – 298K (250J/mol.K)(“frac{1KJ}{10u00b3J}” )

= 100 – 74.5 = 25 5 KJ

“Delta” G⁰ = + postive , the reaction is not spontaneous under room temperature at 298 K

Now we take temperature 410K

“Delta” G⁰ = 100KJ/mol – 410K (250J/mol.K)(“frac{1KJ}{10u00b3J}”)

= 100 – 102.5 = – 2.5 KJ

“Delta” G⁰ = – negative , the reaction is spontaneous at 410K temperature.