Question

What is 1st order kinetics?

Answer 1

1. First-order kinetics is the reaction in which the rate of reaction depends directly on the concentration of one reactant.
2. The rate of reaction is determined by the concentration of one reactant only even though there is more than one reactant involved in the reaction.
3. An example of first-order kinetics is the decomposition of Dinitrogen Pentoxide $\left({\mathrm{N}}_2{\mathrm{O}}_5\right)$into Nitrogen dioxide$\left({\mathrm{NO}}_2\right)$ and Oxygen $\left({\mathrm{O}}_2\right)$.$2{\mathrm{N}}_2{\mathrm{O}}_5\left(\mathrm{g}\right)\to 4{\mathrm{NO}}_2\left(\mathrm{g}\right)+{\mathrm{O}}_2\left(\mathrm{g}\right)$
4. In this reaction, the rate of reaction depends upon the concentration of Dinitrogen Pentoxide.
5. The rate of reaction of any reaction can be calculated by the formula -
   $\mathrm{Rate}=\mathrm{k}{\left[\mathrm{Reactant}\mathrm{concentration}\right]}^{\mathrm{m}}$, where k is the rate constant and m is the order of the reaction.
6. The rate equation for given reaction is shown below.
   $\mathrm{Rate}=\mathrm{k}{\left[{\mathrm{N}}_2{\mathrm{O}}_5\right]}^{\mathrm{m}}$.
7. In the above example of decomposition of Dinitrogen Pentoxide $\left({\mathrm{N}}_2{\mathrm{O}}_5\right)$, the order of the reaction is 1 whereas the stoichiometric coefficient $m=2$ .