So what I want to do is for my delta G value this time,

I'm going to put in a value of 0.

Because I know that I have a positive delta G value.

I want to get to a negative delta G value.

In order to get there, I'm going to have to go through 0, and that's also where

I'll change from being a nonspontaneous process to a spontaneous process.

So I say 0 = and I convert this.

I have my 15,000 joules per mol because

I've already converted my delta H to joules.

Minus T, I don't know that this time,

times my 29.5 joules per mol Kelvin and

when I can rearrange that and

I end up with 15,000 joules per

mol = T x 29.5 joules per mol Kelvin.

And when I solve then I end up with a temperature equal to 508 Kelvin.

And if I subtract 273 from that, I get 235 degrees Celsius.

So at temperatures greater than 235 degrees Celsius I will have a spontaneous

process.

Note that at 25 degrees, we were a non-spontaneous process.

As we go up to 235 we get a delta G greater than zero.

If I continue on past 235,

I'm going to see that my delta G value will now become negative.