Quantitative thermoanalysis of evolved ammonia. Application to ammonium zeolite y and some transition metal ammine chlorides

Abstract

Evolved ammonia is determined quantitatively as a function of temperature. with a suitably modified DuPont 950 thermogravimetric analyzer used in conjunction with a Radiometer automatic titrator. The new technique was applied to ammonium zeolite Y and hexamminenickel(II), tetrammineplatinum(II). and hexammine-cobalt(III) chlorides. For the zeolite, the results show that true hydrogen or acid form of the zeolite is obtained after complete loss of ammonia and before the loss of constitutive water. The stoichiometries of the thermal decompositions of the metal ammines are rapidly elucidated with this technique. Only the cobalt salt was free of impurity as shown by the experimental results. The quantities and some properties of the impurities in the nickel- and platinum-containing salts are determined. Evolved hydrogen chloride may also be measured with the same apparatus. and was determined during the spontaneous reduction of the intermediate Pt(NH3)2Cl2, as well as during the reduction of CoCl2 with hydrogen.