Ionic Equilibria in Aqueous Solutions of the Chlorides of Magnesium, Calcium, Strontium and Barium

The e.m.f. of the cells of the type,

           \(Hg|\begin{smallmatrix} Hg_2Cl_2 HCl&(c_1) \\ MCl_2&(c_2) \end{smallmatrix} \bigr|\)\(\begin{smallmatrix} HCl&(c_1) \\ MCl_2&(c_2) \end{smallmatrix} \bigr|\)\(\begin{smallmatrix} HCl (c_1)&Q.H. \\ MCl_2 (c_2) \end{smallmatrix} \bigr| Pt\)

where M stands for Mg, Ca, Sr or Ba have been measured at one or more temperatures and compared with the values calculated on the basis of complete dissociation of MCl₂. The difference is so small (some times even less than 0·1 mv) that we may safely conclude that the salts are completely dissociated in solutions having ionic strength upto 0·1.