First Order Reaction MCQ - Practice Questions with Answers

  can be taken as the time taken for the concentration of a reactant to drop to 3/4 of its initial value. If the rate constant for a first order reaction is the    can be written as

The rate equation for the reaction is found to be : rate The correct statement in relation to this reaction is that the

The half-life period of a first-order reaction is 15 minutes. The amount of substance left after one hour will be :

Units of the rate constant of first and zero-order reactions in terms of molarity M unit are respectively.

A bacterial infection in an internal wound grows as $N^{\prime}(t)=N_o \exp (t)$, where the time $t$ is in hours. A dose of antibiotic, taken orally, needs 1 hour to reach the wound.

Once it reaches there, the bacterial population goes down as $\frac{d N}{d t}=-5 N^2$.
What will be the plot of $\frac{N_o}{N}$ vs. t after 1 hour?

The decomposition of phosphine (PH₃) on tungsten at low pressure is a first-order reaction. It is because the

A reaction is 50% completed in 2 hours and 75% completed in 4 hours. The order of the reaction is

Select the reaction which does not follow the first order Kinetics:

If we start a reaction from 100 mol, the rate constant is $0.0693 \mathrm{~min}^{-1}$. What will be the rate of the reaction offer 20 min?

Which of the following reactions is first order reaction?