Question

At 400K, the half-life of a sample of a gaseous compound initially at 56.0 $kPa$ is 340s. When the pressure is 28.0 $kPa$, the half-life is 170s. The order of the reaction is:

• A. 0
• B. 2
• C. 1
• D. 1/2

Answer 1

The correct option is A 0

When the pressure is reduced to half from 56.0 kPa to 28 kPa, the half-life period is reduced to half from 340 s to 170 s.

Thus, the half-life period is proportional to the pressure. This is true for a zero-order reaction.