Theoretical Study on the Extraction of Alkaline Earth Salts by 18-Crown-6: Roles of Counterions, Solvent Types and Extraction Temperatures - Hadisaputra, Saprizal; Chemistry Education Division, Faculty of Teacher Training and Science Education, Universitas Mataram, Jl. Majapahit 62, Mataram 83251 (Universitas Gadjah Mada, 2014)