Question

At 345 K, the half life for the decomposition of a sample of a gaseous compound initially at 55.5 kPa was 340 s. When the pressure was 27.8 kPa, the half life was found to be 170 s. The order of the reaction is ________. [integer answer]

Answer 1

$t_{\frac{1}{2}}∝\frac{1}{|P_o|^{n-1}}$

$\frac{(t_{1/2})_1}{(t_{1/2})}=\frac{|P_0|_2^{n-1}}{|P_0|_1^{n-1}}$

$\frac{340}{170}=(\frac{27.8}{55.5})^{n-1}$

$2=(\frac{1}{2})^{n-1}$

2 = (2)1 – n

1 – n = 1

n = 0