Enthalpy of Solution vs Temperature

[Mike4chemic]

Hello,
I am looking for a simple way to describe the dependence between the enthalpy of solution (e.g carbon dioxide (g) in hot water) and temperature.

Thanks in advance,

Mike

 

[dcasto]

The enthalpy of solution is constant (or very close) for different temperatures. What happens is as the CO2 is added, the temperature rise due to the heat of absorption cause the system temperature to rise. As the sytemabsortion temperature rises, the equalibrium of CO2 in water drops and the CO2 will not absorb. Once the solution is saturated with CO2, the temperature will stop rising because the is no more heat of solution.

 

[Mike4chemic]

dcasto,

Thank you very much.

P.S. What is the sytemabsortion?

Regards,

Mike

 

[25362]

The temperature dependence of the solubility of gases is given by the relation

dlnc/dT = [Δ]H_sol/RT²​

where c is the number of moles of gas dissolved in a definite volume of solvent and [Δ]H_sol is the molar heat of solution, assumed constant in the given temperature interval.

Since values of c as function of T are amply tabulated, one could solve for the molar heat of solution from:

log(c₂/c₁) = - ([Δ]H_sol/2.303R)(1/T₂-1/T₁)​

2.303R can be replaced by 4.576, and T are in Kelvin.

 

[dcasto]

As the system temperature...