JEE Advanced · 2020 · 27 Sep 2020 · Paper 2 · Chemical Kinetics

For a reversible reaction $\mathbf{R}\rightleftharpoons \mathbf{P}$, at constant temperature, both the forward and the backward reactions are first order elementary reactions with rate constant $k_f$ and $k_b$, respectively. At time zero, the concentration of …

For a first-order reaction $\mathbf{R}\to \mathbf{P}$ at a given temperature, $k$ is the rate constant. For this reaction, at the given temperature, the concentrations of $\mathbf{R}$ and $\mathbf{P}$ at a time $t$ are $[\mathbf{R}]$ and $[\mathbf{P}]$, respectively. The …

Consider a reaction $A+R\to$ Product. The rate of this reaction is measured to be $k[A][R]$. At the start of the reaction, the concentration of $R,[R{]}_0$, is 10-times the concentration of $A,[A{]}_0$. The reaction can be considered to be a pseudo first order reaction w …

Consider the following reaction,

which follows the mechanism given below: …

A sample initially contains only U-238 isotope of uranium. With time, some of the U-238 radioactively decays into Pb-206 while the rest of it remains undisintegrated.
When the age of the sample is $\mathbf{P}\times 10^8$ years, the ratio of mass of $\mathrm{Pb}-206$ to tha …

The plot of $\log {\mathrm{k}}_{\mathrm{f}}$ versus $\frac{1}{\mathrm{T}}$ for a reversible reaction $\mathrm{A}(\mathrm{g})\rightleftharpoons \mathrm{P}(\mathrm{g})$ is shown.

(see plot)

Pre-exponential factors for the forward and backward reactions are …