Two more for the champs

[CasanovaFrankenstein]

Well, I've been impressed - to say the least - with how quickly my questions have been answered. So, here are two more:

N2O4 --> 2NO2

Under standard conditions: Delta G is 2.8 kJ. What temp will make it spontaneous?

And

What amount of Cd(OH)2 will dissolved in 1.00 x 10^2 L of aq. solution?

Any takers? Thanks in advance

[GCT]

Under standard conditions: Delta G is 2.8 kJ. What temp will make it spontaneous?

You'll simply need to find an appropriate equation for this one. Suggest one to us.

What amount of Cd(OH)2 will dissolved in 1.00 x 10^2 L of aq. solution?

This is also a basic problem. What's the Ksp? What can you do from there?

[gravenewworld]

G=H-TS

You should have a table of standard state enthalpy and entropy data somewhere in your book, probably the back. Thus calculate delta H and delta S for the reaction. In order to find a temperature to make the reaction spontaneous you want H-TS<0 or H<TS or T<H/S (be careful of the sign here, you may have to flip it if S is negative).