Solutions of electrolytes in liquid ammonia. Part V. Ion-pair formation by ammonium nitrate and ammonium iodide in liquid ammonia at –40 °C

Abstract

Ion-pair and triple ion formation constants (K_A and K_T) have been obtained for NH₄NO₃ and NH₄I in liquid ammonia at –40 °C from previously reported activity coefficient measurements. For NH₄NO₃, K_A= 401 ± 9 dm³ mol^–1 and K_T= 11·4 ± 0·7 dm³ mol^–1, and for NH₄I, K_A= 476 ± 20 dm³ mol^–1 and K_T= 6·5 ± 0·8 dm³ mol^–1, when the size parameter in the Debye–Hückel equation is set at the Bjerrum critical distance (16·22 × 10^–10 m). Revised activity coefficients based on this analysis are presented.