description
I have a question about the $m_f$ vs. $\Delta_{\text{dil}} H$ plot in some experimental studies.
For example, the dilution-of-enthalpy data at 300 °C with two initial concetration ($m_i$) 0.2470 and 0.5199 are reported as follows:
- $m_i$: initial concentration
- $m_f$: final concentration
then the author did the visualization by using $m_f$ vs. $\Delta_{\text{dil}} H$ like this:
however, when I try to do the same, I got:
it seems that the author explained a little under the diagram:
At each temperature, a constant was added to the heats of dilution for the solution with the lower initial concentrations so that the zero value for these solutions would correspond to the zero value of the solution having a higher initial concentration
but it is not very clear to me, could anybody explain a little bit about this? How a constant could be determined for all the enthalpies of solutions with lower initial concentrations?
reference
Oscarson, J. L., Gillespie, S. E., Chen, X., Schuck, P. C., & Izatt, R. M. (2001). Enthalpies of Dilution of Aqueous Solutions of HCl, MgCl2}, CaCl2, and BaCl2 at 300, 325, and 350° C. Journal of solution chemistry, 30, 31-53.
