EFFECTS OF PARTICLE-SIZE ON THE DECOMPOSITION OF AMMONIUM CARBONATE

The decomposition of ammonium carbonate having three different particl e size distributions has been studied by DSC. The samples consisted of large particles (302 +/- 80 mu m), intermediate particles (98 +/- 36 mu m) obtained by grinding the larger particles, and small particles ( 30 +/- 10 mu m) obtained by fracturing the large particles with ultras ound. Data from the decomposition of the intermediate particles gave t he best fit with a first-order rate law. The bulk of the data for deco mposition of the larger particles followed either a D3 or F1 rate law while a D3 rate law fit most of the data from decomposition of the sma llest particles.