In: Chemistry
Write a reaction for the dissolution of fluorite (CaF2) in water. Calculate the change in enthalpy, entropy and free energy for this reaction at 25°C
Dissolution of CaF2 is
CaF2(s) + H2O(l) ------------------- CaF2(aq)
Chnage in enthalpy = H= Hf of CaF2(aq) - [Hf of CaF2(s) + Hf of H2O]
=-1184.07 -[-1219.64 -285.83]
H= 321.4 KJ
Change in entropy =S= Sf of CaF2(aq) - [ Sf of CaF2(s) + Sf of H2O]
= 92.59 -[68.87+69.91]
S = -46.19J
G = H - T S T= 25C = 25+273 = 298K
G = 321.4KJ - [298x(-46.19J)]
G = 335.164KJ
G = 335.16KJ.