No abstract

No abstract

The stoichiometric equilibrium constant, K′ , for the autosolvolysis reaction for the aluminum chloride‐1‐methyl‐3‐ethylimidazolium chloride ionic liquid was investigated as a function of temperature with a chloroaluminate concentration cell and aluminum electrodes. The values obtained at 40°, 50°, and 60°C for logK′ were −16.3±0.1 , −16.1±0.6 , and −15.5±0.2 . The enthalpy change for the autosolvolysis reaction was found to be approximately 80 kJ · mol−1 over this temperature range. A curve fitting method for determining the initial composition of this ionic liquid during a titration is also described.

Equilibrium constants were calculated for reactions governing the species present at 175°C in molten mixtures of aluminum chloride and sodium chloride. The equilibria postulated pertain to formation of the complex ions AlCl4− , Al2Cl7− , and Al3Cl10− from Cl− , AlCl3 , and Al2Cl6 . The constants were derived from potentials exhibited by concentration cells of the type normalAl/AlCl3false(Nfalse) , normalNaCl//AlCl3false(N′false) , normalNaCl/normalAl , and from vapor pressures over pure AlCl3 and molten AlCl3‐normalNaCl mixtures. Measurements were made throughout the concentration range N=0.498–0.71 . The possibilities of using these concentration cells as high energy density batteries are considered.