At 500 K, the half-life period of a gaseous reaction at the initial pressure of 80 kPa is 350 sec. When the pressure is 40 kPa, the half life period is 175 sec. The order of reaction is

Options

A. zero
B. one
C. two
D. three

Answer

A

Explanation

When initial pressure is halved, the half-life period is also halved. This shows that `t_(1//2) prop` initial pressure. This is so for reactions of zero order.