1.

greatest soubility in water of a substance is the one it has the greater Ksp

Ksp 1.3x10^-7 this one is the correct

Ksp 3.5x10^-8

2.

I HAVE A DISSOLUTION OF SODIU NITRATE IN WATER THIS OCURS INSTANTANEOUSLY, TEMP WATER DECRESSES,

AH<0, AS<0, AS<0 IS THE ANSWER I CAME UP WITH

I indestand spentaneous reactions has to be <0 but im not sure about the rest..

3

and this one I canT FIGURED OUT,

Use the following thermodynamic data

Species---ΔH°(kJ/mol)------S°(J/K mol)

H2O2(l) -187.78---------+109.6

H2O(l) -285.83----------+69.91

O2(g) 0---------------+205.14

to calculate ΔS°univ for the decomposition of hydrogen peroxide at 25.0°C.

2 H2O2(l) → 2 H2O(l) + O2(g)

a.-783.8 J/K

b.-531.9 J/K

c.+494.2 J/K

d.+783.8 J/K

e.+3741 J/K

what im doing is using

ASuniv=AS sys+AS surrandings

and to find ASsurran im using

ASsurr=-AHrxn/T So

ASsurr=(2-(-285.83))/298K

=-1.9183 kJ and convert to J/K is -1918.3 J/K

then

ASsystem (2(69.91)+205.14)-(2(109.6))= 125.76

then add ASsysm+Asurra=-1793.3

what am i doing wrong?

thanks i lot for your help

ziccoh