The half-life of decomposition of gaseous `CH_(3)CHO` at initial pressure of `365 mm` and `170 mm` of `Hg` were `420 sec` and `880 sec` respectively. The order of the reaction is:

The half-life for a reaction at initial concentration of 0.5 and 1.0 "mole litre"^(-1) are 200 sec and 100 sec respectively. The order of the reaction is

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

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

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

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

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