Mechanism of a Chemical Reaction

For next two question please follow the same

 If in a unimolecular reaction, $\text{A}\left(\mathrm{g}\right)⟶$ products takes place according to the mechanism

I. $\text{A}+\text{A}\underset{{\text{k}}_{-1}}{\overset{{\text{k}}_1}{\rightleftharpoons }}{\text{A}}^{*}+\text{A}$

II. ${\text{A}}^{*}\underset{{\text{k}}_2}{⟶}\text{P}$

where ${\text{k}}_1\text{, }{\text{k}}_{-1}$ ${\text{k}}_2$ are the rate constants and P, $\mathrm{A}$ and ${\text{A}}^{*}$ stand for product molecule, normal molecules of reactants and activated molecules of reactants respectively.

Which of the following expressions are correct?

The reaction between ${\mathrm{H}}_2 \left(\mathrm{g}\right)$ and $\mathrm{ICl} \left(\mathrm{g}\right)$occurs in the following steps:
$\text{ (i) }{\mathrm{H}}_2+\mathrm{ICl}⟶\mathrm{HI}+\mathrm{HCl}$

$\text{ (ii) }\mathrm{HI}+\mathrm{ICl}⟶{\mathrm{I}}_2+\mathrm{HCl}$

The reaction intermediate in the reaction is

Identify the correct potential energy vs reaction co-ordinate graph, which is consistent with given mechanism.

The mechanism of esterification in presence of acid catalyst (H₂SO₄) is proposed as follows:

Which of the following is compound?

In the steady state approximation, if $\mathrm{I}$ is the intermediate formed, then

The mechanism of esterification in presence of acid catalyst $\left(H_{2}S{O}_4\right)$ is proposed as follows:



Which of the following potential energy vs reaction co-ordinate diagram is consistent with given mechanism?

STATEMENT-1: $\mathrm{N}{\mathrm{O}}_2+\mathrm{C}\mathrm{O}\to \mathrm{C}{\mathrm{O}}_2+\mathrm{N}\mathrm{O}$

$\mathrm{r}=\mathrm{k}\left[\mathrm{N}{\mathrm{O}}_2\right]$

The rate of the above reaction is independent of the concentration of CO

STATEMENT-2: The rate does not depend upon [CO] because it is involved in fast step.

A hypothetical reaction ${\mathrm{A}}_2+{\mathrm{B}}_2\to 2\mathrm{A}\mathrm{B}$ follows the mechanism as given below:

${\mathrm{A}}_2{}_{\leftarrow }{}^{\to }\mathrm{A}+\mathrm{A}\left(\mathrm{fast}\right)$
$\mathrm{A}+{\mathrm{B}}_2\to \mathrm{A}\mathrm{B}+\mathrm{B}\mathrm{ }\left(\mathrm{s}\mathrm{l}\mathrm{o}\mathrm{w}\right)$

$\mathrm{A}+\mathrm{B}\to \mathrm{A}\mathrm{B}\mathrm{ }\left(\mathrm{f}\mathrm{a}\mathrm{s}\mathrm{t}\right)$

What will be the order of the overall reaction?

The reaction: $2\mathrm{N}\mathrm{O}+2{\mathrm{H}}_2\to {\mathrm{N}}_2+2{\mathrm{H}}_2\mathrm{O}$ has been assigned to follow given mechanism:

I. $\mathrm{N}\mathrm{O}+\mathrm{N}\mathrm{O}\rightleftharpoons {\mathrm{N}}_2{\mathrm{O}}_2\mathrm{ }\left(\mathrm{f}\mathrm{a}\mathrm{s}\mathrm{t}\right)$

II. ${\mathrm{N}}_2{\mathrm{O}}_2+{\mathrm{H}}_2\to {\mathrm{N}}_2\mathrm{O}+{\mathrm{H}}_2\mathrm{O}\mathrm{ }\left(\mathrm{s}\mathrm{l}\mathrm{o}\mathrm{w}\right)$

III. ${\mathrm{N}}_2\mathrm{O}+{\mathrm{H}}_2\to {\mathrm{N}}_2+{\mathrm{H}}_2\mathrm{O}\mathrm{ }\left(\mathrm{f}\mathrm{a}\mathrm{s}\mathrm{t}\right)$

The rate constant of step II is $1.2\times {10}^4\mathrm{ }\mathrm{m}\mathrm{o}\mathrm{l}{\mathrm{e}}^{-1}\mathrm{ }\mathrm{L}\mathrm{ }{\mathrm{m}\mathrm{i}\mathrm{n}}^{-1}$ while equilibrium constant of step I is $1.4\times {10}^2$ . What is the rate of reaction when concentration of $\mathrm{NO}$ and ${\mathrm{H}}_2$ each is $0.5$mole ${\mathrm{L}}^{-1}$

In a multistep reaction, find out the overall rate of reaction:

Consider this reaction :

$2\mathrm{ }{\mathrm{N}\mathrm{O}}_2\mathrm{ }\left(\mathrm{g}\right)+{\mathrm{O}}_3\mathrm{ }\left(\mathrm{g}\right)\mathrm{ }⟶\mathrm{ }{\mathrm{N}}_2{\mathrm{O}}_5\mathrm{ }\left(\mathrm{g}\right)+{\mathrm{O}}_2\mathrm{ }\left(\mathrm{g}\right)$

The rate law for the above reaction is given as $\mathrm{rate}=\mathrm{k}\left[{\mathrm{NO}}_2\right]\left[{\mathrm{O}}_3\right]$.  Which of the following mechanism is/are consistent with the rate law?
$\mathrm{Mechanism} \mathrm{I}$

${\mathrm{NO}}_2\mathrm{ }\left(\mathrm{g}\right)+{\mathrm{O}}_3\mathrm{ }\left(\mathrm{g}\right)\mathrm{ }\stackrel{\mathrm{Slow} }{\to }{\mathrm{N}\mathrm{O}}_3\mathrm{ }\left(\mathrm{g}\right)+{\mathrm{O}}_2\mathrm{ }\left(\mathrm{g}\right)$

${\mathrm{N}\mathrm{O}}_3\mathrm{ }\left(\mathrm{g}\right)+{\mathrm{N}\mathrm{O}}_2\mathrm{ }\left(\mathrm{g}\right)\mathrm{ }\stackrel{\mathrm{ }\mathrm{fast}}{\to }{\mathrm{N}}_2{\mathrm{O}}_5\mathrm{ }\left(\mathrm{g}\right)$

$\mathrm{Mechanism} \mathrm{II}$

$:{\mathrm{O}}_3\mathrm{ }\left(\mathrm{g}\right)\rightleftarrows \mathrm{ }{\mathrm{O}}_2\mathrm{ }\left(\mathrm{g}\right)+\mathrm{O}\mathrm{ }$

${\mathrm{N}\mathrm{O}}_2\mathrm{ }\left(\mathrm{g}\right)+\mathrm{O}\mathrm{ }\stackrel{\mathrm{slow}}{\to }{\mathrm{N}\mathrm{O}}_3\mathrm{ }\left(\mathrm{g}\right)\mathrm{ }$

${\mathrm{N}\mathrm{O}}_3\mathrm{ }\left(\mathrm{g}\right)+{\mathrm{N}\mathrm{O}}_2\mathrm{ }\left(\mathrm{g}\right)\mathrm{ }\stackrel{\mathrm{fast}}{\to }{\mathrm{N}}_2{\mathrm{O}}_5\mathrm{ }\left(\mathrm{g}\right)\mathrm{ }$

The mechanism of the following reaction is:

$2\mathrm{N}\left(\mathrm{g}\right)+2{\mathrm{H}}_2\mathrm{ }\left(\mathrm{g}\right)\mathrm{ }⟶{\mathrm{N}}_2\mathrm{ }\left(\mathrm{g}\right)+2{\mathrm{H}}_2\left(\mathrm{g}\right)$

Step 1$:2\mathrm{N}\left(\mathrm{g}\right)+2{\mathrm{H}}_2\mathrm{ }\left(\mathrm{g}\right)\mathrm{ }\stackrel{\mathrm{slow}}{\to }{\mathrm{N}}_2\mathrm{ }\left(\mathrm{g}\right)+{\mathrm{H}}_2$

Step 2$:2{\mathrm{H}}_2+{\mathrm{O}}_2\stackrel{\mathrm{f}\mathrm{a}\mathrm{s}\mathrm{t}}{\to }\mathrm{ }2{\mathrm{H}}_2\mathrm{O}$

Which of the following statements is true-

As per the following consecutive reactions the r.d.s. is

(P) $\stackrel{\mathrm{k}=2\times {10}^{-5}{\mathrm{s}}^{-1}}{\to }$

(Q) $\stackrel{\mathrm{k}=8\times {10}^{-6}{\mathrm{s}}^{-1}}{\to }$

(R) $\stackrel{\mathrm{k}=3\times {10}^{-3}{\mathrm{s}}^{-1}}{\to }$

(S)

For reaction $2\mathrm{A}+\mathrm{B}⟶\mathrm{D}+\mathrm{E}$, following mechanism has been proposed$\mathrm{ }\mathrm{A}+\mathrm{B}⟶\mathrm{C}+\mathrm{D} \left(\mathrm{Is} \mathrm{slow}\right)$ and $\mathrm{A}+\mathrm{C}⟶\mathrm{E}\mathrm{ }\left(\mathrm{Is} \mathrm{fast}\right)$.

The following mechanism is proposed for the reaction of $\mathrm{N}\mathrm{O}$ with ${\mathrm{B}\mathrm{r}}_2$ to from $\mathrm{N}\mathrm{O}\mathrm{B}\mathrm{r}$

$\mathrm{N}\mathrm{O}\left(\mathrm{g}\right)+{\mathrm{B}\mathrm{r}}_2\left(\mathrm{g}\right)\rightleftharpoons {\mathrm{N}\mathrm{O}\mathrm{B}\mathrm{r}}_2\left(\mathrm{g}\right)$

${\mathrm{N}\mathrm{O}\mathrm{B}\mathrm{r}}_2\left(\mathrm{g}\right)+\mathrm{N}\mathrm{O}\left(\mathrm{g}\right)⟶2\mathrm{N}\mathrm{O}\mathrm{B}\mathrm{r}\left(\mathrm{g}\right)$

If the second step is considered as the rate determining step, the order of the reaction with respect to $\mathrm{N}\mathrm{O}\left(\mathrm{g}\right)$ is

Select the intermediate in the following reaction:

$2{\mathrm{O}}_3⟶3{\mathrm{O}}_2$

Step (a) ${\mathrm{O}}_3\left(\mathrm{g}\right)\rightleftharpoons {\mathrm{O}}_2\left(\mathrm{g}\right)+\mathrm{O}\left(\mathrm{g}\right)$

Step (b)$\mathrm{ }\mathrm{O}\left(\mathrm{g}\right)+{\mathrm{O}}_3\left(\mathrm{g}\right)⟶2{\mathrm{O}}_2$

The rate constant $\left({\text{K}}^{\prime }\right)$ of one reaction is double of the rate constant $\left({\text{K}}^{″}\right)$ of another reaction. Then the relationship between the corresponding activation energies of the two reactions (${\text{E}}_{\text{a}}^{\prime }$ and ${\text{E}}_{\text{a}}^{″}$) will be

Consider the following parallel reactions being given by A (t_1/2 = 1.386 × 10² hours), each path being 1^st order.



If distribution of A in the product mixture is 50%, calculate partial half-life of A for the conversion into B.

Give the hypothetical reaction mechanism

$\mathrm{A}\stackrel{\mathrm{ }\mathrm{ }\mathrm{ }\mathrm{I}\mathrm{ }\mathrm{ }\mathrm{ }\mathrm{ }\mathrm{ }\mathrm{ }\mathrm{ }}{\to }\mathrm{B}\stackrel{\mathrm{ }\mathrm{ }\mathrm{ }\mathrm{I}\mathrm{I}\mathrm{ }\mathrm{ }\mathrm{ }\mathrm{ }\mathrm{ }\mathrm{ }\mathrm{ }}{\to }\mathrm{C}\stackrel{\mathrm{ }\mathrm{ }\mathrm{ }\mathrm{I}\mathrm{I}\mathrm{I}\mathrm{ }\mathrm{ }\mathrm{ }\mathrm{ }\mathrm{ }\mathrm{ }\mathrm{ }}{\to }\mathrm{D}\stackrel{\mathrm{ }\mathrm{ }\mathrm{I}\mathrm{V}\mathrm{ }\mathrm{ }\mathrm{ }\mathrm{ }\mathrm{ }\mathrm{ }\mathrm{ }}{\to }\mathrm{E}$ and the rate as
 

Consider the reaction,

${\mathrm{Cl}}_2\left(\mathrm{aq}\right)+{\mathrm{H}}_2\mathrm{S}\left(\mathrm{aq}\right)\to \mathrm{S}\left(\mathrm{s}\right)+2{\mathrm{H}}^{+}\left(\mathrm{aq}\right)+2{\mathrm{Cl}}^{-}\left(\mathrm{aq}\right)$ The rate equation for this reaction is, rate $=$ $\mathrm{k}\left[{\mathrm{Cl}}_2\right]\left[{\mathrm{H}}_2\mathrm{S}\right]$

Which of these mechanisms is/are consistent with this rate equation?

A.  ${\mathrm{Cl}}_2+{\mathrm{H}}_2\mathrm{S}\left(\mathrm{aq}\right)\to {\mathrm{H}}^{+}{\mathrm{Cl}}^{-}+{\mathrm{Cl}}^{+}+{\mathrm{HS}}^{-} \left(\mathrm{slow}\right)$

${\mathrm{Cl}}^{+}+{\mathrm{HS}}^{-}\to {\mathrm{H}}^{+}{\mathrm{Cl}}^{-}+\mathrm{S} \left(\mathrm{fast}\right)$

B. ${\mathrm{H}}_2\mathrm{S}\leftrightarrow {\mathrm{H}}^{+}+{\mathrm{HS}}^{-}\left(\mathrm{fast}\mathrm{ }\mathrm{equilibrium}\right)$

${\mathrm{Cl}}_2+{\mathrm{HS}}^{-}\to 2{\mathrm{Cl}}^{-}+{\mathrm{H}}^{+}\mathrm{S} \left(\mathrm{slow}\right)$