A reaction takes \(30\, \ minutes\) to complete \(50\%\) of the reaction and takes \(45\, \ minutes\) to complete \(75\%\) of the reaction. The order of the reaction is:
Answer & explanation
Correct answer: option 4
The correct answer is option 4. Zero.
The problem provides two data points:
30 minutes for \(50\%\) completion \((t_1)\)
45 minutes for \(75\%\) completion \((t_2)\)
The key point for a zero-order reaction is that the time difference (Δt) between reaching different percentages of completion should be constant.
\(Δt\)= \(t_2 – t_1 = 45\, \ min – 30\, \ min = 15\, \ min\)
In this case, the observed time difference is 15 minutes, it is a constant value for reaching every 25% completion (from 50% to 75%). This observation aligns with the characteristic behavior of a zero-order reaction.
While the increasing percentage of completion does lead to a time difference, the constant time difference (15 minutes for every 25% increase) suggests that the reaction rate is independent of the concentration throughout the process. This points towards a zero-order reaction.
Therefore, the correct answer is indeed 4. Zero.