[Sis290025]

Determine the standard free energy of an unknown solid MX2 having a molar solubility of 2.4500 x 10-6 at 25°C.Give you answer in Kilojoules.

DeltaG* = -RTlnK
= -(8.314) (298.15 K)ln(2.45E-6)
= -(-32024.91134 J)
=+ 32.024911  kJ = 32.02 kJ


If a reaction has change in enthalpy of 9.3 kJ and a change in entropy of 7.6 J/K, what is the gibbs free energy change at 45 degrees Celsius?Report your answer in kJ .Report your answer to three significant figures.
T = 45 C + 273.15 = 318.15 K

deltaG = deltaH - deltaS(T)
= 9.3 kJ - (318.15 K)(0.0076 kJ/K)
= 9.3 kJ - (2.41794 kJ)
= 6.88 kJ

Thanks.

[Albert]

Both correct.