Where y = wt /w0 and wt = weight remaining at time, ‘t’, wo = initial weight, T = temperature in Kelvin scale. From the resid- ual weight of the sample, ln[ln(1/y)] was plotted against 1/T in order to obtain Fig. 7(b). From the slope of the linear portion (Arrhenius plot) which is ‘−E/R’ (R, universal gas constant