Rate Law & Rate Constant — IISER Chemistry MCQs with Solutions

For a reaction that is first order overall, $Rate=k[A]$. The units of the rate constant $k$ are:

For a zero-order reaction, $Rate=k$. The units of the rate constant $k$ are:

For a reaction that is second order overall, $Rate=k[A]^2$. The units of the rate constant $k$ are:

A reaction has the experimentally determined rate law $Rate=k[NO]^2[H_2]$. Its overall order is:

For a reaction with $Rate=k[A]^3$, if the concentration of $A$ is doubled the rate becomes:

Which of the following quantities is independent of the concentrations of the reactants?

The value of the rate constant of a reaction is changed by altering the:

The rate constant is called the specific reaction rate because it is numerically equal to the reaction rate when the concentration of each reactant is:

For a reaction with $Rate=k[A]$, if the concentration of $A$ is reduced to half, the rate becomes:

For a zero-order reaction, the rate of reaction is:

For a reaction with $Rate=k[A]^2[B]$, if only $[A]$ is doubled the rate becomes:

For a reaction with $Rate=k[A][B]^2$, if only $[B]$ is tripled the rate becomes:

For $X + Y \rightarrow$ products the initial-rate data are: Exp 1 $[X]=0.10,\,[Y]=0.10$, rate $=1.5\times10^{-3}$; Exp 2 $[X]=0.20,\,[Y]=0.10$, rate $=3.0\times10^{-3}$; Exp 3 $[X]=0.10,\,[Y]=0.30$, rate $=1.35\times10^{-2}$ (all in $mol,\,L,\,s$ units). The rate law is:

For $X + Y \rightarrow$ products with $Rate=k[X][Y]^2$, Exp 1 gives $[X]=0.10\,M,\,[Y]=0.10\,M$ and rate $=1.5\times10^{-3}\,mol\,L^{-1}s^{-1}$. The rate constant $k$ is:

For $2A + B \rightarrow$ products the data are: Exp 1 $[A]=0.10,\,[B]=0.20$, rate $=4.0\times10^{-3}$; Exp 2 $[A]=0.20,\,[B]=0.20$, rate $=1.6\times10^{-2}$; Exp 3 $[A]=0.10,\,[B]=0.40$, rate $=4.0\times10^{-3}$ (mol, L, s). The orders with respect to $A$ and $B$ are, respectively:

For $2A + B \rightarrow$ products the rate law is $Rate=k[A]^2$. Exp 1 gives $[A]=0.10\,M$ and rate $=4.0\times10^{-3}\,mol\,L^{-1}s^{-1}$. The rate constant $k$ is:

For $A + B \rightarrow C$ the data are: Exp 1 $[A]=0.05,\,[B]=0.05$, rate $=2.0\times10^{-3}$; Exp 2 $[A]=0.10,\,[B]=0.05$, rate $=4.0\times10^{-3}$; Exp 3 $[A]=0.10,\,[B]=0.15$, rate $=1.2\times10^{-2}$ (mol, L, s). The rate law and overall order are:

For $A + B \rightarrow C$ with $Rate=k[A][B]$, Exp 1 gives $[A]=0.05\,M,\,[B]=0.05\,M$ and rate $=2.0\times10^{-3}\,mol\,L^{-1}s^{-1}$. The rate constant $k$ is:

A first-order reaction has $Rate=k[A]$ with $k=0.025\,s^{-1}$. At an instant when the rate is $5.0\times10^{-3}\,mol\,L^{-1}s^{-1}$, the concentration of $A$ is:

A second-order reaction has $Rate=k[A]^2$ with $k=2.0\,L\,mol^{-1}s^{-1}$. When $[A]=0.30\,M$, the rate of the reaction is:

For a reaction with $Rate=k[A]^2[B]$, if $[A]$ is halved and $[B]$ is quadrupled, the rate becomes:

A reaction has $Rate=k[A]^{1/2}[B]$. If $[A]$ is increased $4$-fold and $[B]$ is increased $3$-fold, the rate becomes:

For a reaction with $Rate=k[A]^2[B]$, if $[A]$ is doubled and $[B]$ is tripled, the rate becomes:

Which one of the following statements is correct?

Which of the following statements about the order of a reaction is INCORRECT?

Assertion (A): The rate constant of a reaction has a definite value only when the temperature is specified. Reason (R): The rate constant depends on temperature through the Arrhenius equation but is independent of the reactant concentrations. Which is correct?

For a reaction with $Rate=k[A]^2$, the temperature is raised so that $k$ doubles while at the same time $[A]$ is halved. The new rate compared with the original is:

For $A + B \rightarrow$ products the data are: Exp 1 $[A]=0.10,\,[B]=0.10$, rate $=2.0\times10^{-2}$; Exp 2 $[A]=0.30,\,[B]=0.10$, rate $=1.8\times10^{-1}$; Exp 3 $[A]=0.10,\,[B]=0.20$, rate $=2.0\times10^{-2}$ (mol, L, s). The overall order of the reaction is:

For the reaction $A + B \rightarrow$ products above, with $Rate=k[A]^2$, Exp 1 gives $[A]=0.10\,M$ and rate $=2.0\times10^{-2}\,mol\,L^{-1}s^{-1}$. The rate constant $k$ is:

For the same reaction ($Rate=k[A]^2$, $k=2.0\,L\,mol^{-1}s^{-1}$), the initial rate when $[A]=0.20\,M$ is: