Okay so I'm confused. In my book it says that ksp for Ca(OH)2 = 6.5E-6 and [tex]\Delta G=-898.5[/tex] yet when I use the equation [tex]\Delta G=-RTln(Ksp)[/tex] the value I get is 29.59KJ/mol. I used R=8.314 and T=298K. What's up with that? Thanks.