For a reaction taking place in three steps at same temperature, o… - Vidyadip

MCQ

For a reaction taking place in three steps at same temperature, overall rate constant $\mathrm{K}=\frac{\mathrm{K}_1 \mathrm{~K}_2}{\mathrm{~K}_3}$. If $\mathrm{Ea}_1, \mathrm{Ea}_2$ and $\mathrm{Ea}_3$ are $40$,$50$ and $60 \mathrm{~kJ} / \mathrm{mol}$ respectively, the overall $\mathrm{Ea}$ is ________ $\mathrm{kJ} / \mathrm{mol}$.

A
$20$
B
$10$
✓
$30$
D
$45$

✓

Answer

Correct option: C.

$30$

c
$ \mathrm{K}=\frac{\mathrm{K}_1 \cdot \mathrm{K}_2}{\mathrm{~K}_3}=\frac{\mathrm{A}_1 \cdot \mathrm{A}_2}{\mathrm{~A}_3} \cdot \mathrm{e}^{-\frac{\left(\mathrm{E}_{\mathrm{a}_1}+\mathrm{E}_{\mathrm{a}_2}-\mathrm{E}_{\mathrm{a}_3}\right)}{R T}} $

$ \mathrm{~A} \cdot \mathrm{e}^{-\mathrm{E}_{\mathrm{a}} / \mathrm{RT}}=\frac{\mathrm{A}_1 \mathrm{~A}_2}{\mathrm{~A}_3} \cdot \mathrm{e}^{-\frac{\left(\mathrm{E}_{\mathrm{a}_1}+\mathrm{E}_{\mathrm{a}_2}-\mathrm{E}_{\mathrm{a}_3}\right)}{R T}}$

$\mathrm{E}_{\mathrm{a}}=\mathrm{E}_{\mathrm{a}_1}+\mathrm{E}_{\mathrm{a}_2}-\mathrm{E}_{\mathrm{a}_3}=40+50-60=30 \mathrm{~kJ} / \mathrm{mole}$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

NEET STD 11 Science question papers→Gujarat Board STD 11 Science question papers→Gujarat Board question paper generator→

Similar questions

Sodium chloride easily dissolves in water. This is because

Nitration of toluene takes place at

At $298\, K$, the standard reduction potentials are $1.51\, V$ for $MnO_4^ - \,|\,M{n^{2 + }}$, $1.36\, V$ for $C{l_2}\,|\,C{l^ - }$, $1.07\, V$ for $B{r_2}\,|\,B{r^ - }$ and $0.54\, V$ for ${I_2}\,|\,{I^ - }$. At $pH\, = 3$ , permanganate is expected to oxidize $\left( {\frac{{RT}}{F} = 0.059\,V} \right)$

Select correct statement about anionic part of Zeise’s salt, $K\left[ {Pt\left( {{\eta ^2} - {C_2}{H_4}} \right)C{l_3}} \right]$

For a certain reaction, $10\%$ of the reactant dissociates in $1\, hour$, $20\%$ of the reactant dissociate in $2\, hour$, $30\%$ of the reactant dissociates in $3\, hour$. Then the units of rate constant is

The solubility product for a salt of the type $AB$ is $4 \times 10^{-8}$. What is the molarity of its standard solution?

The equlilibrium constant for the following general reaction is $10^{30}$. Calculate $E^o$ for the cell at $298\, K$. .............. $\mathrm{V}$

$2{X_2}\left( s \right) + 3{Y^{ + 2}}\left( {aq} \right) \to 2X_2^{3 + }\left( {aq} \right) + 3Y\left( s \right)$

Total stereo isomers of the complex

${{\text{[Fe(F)(Cl)(Br)(I)(N}}{{\text{H}}_3}{\text{)(}}{{\text{H}}_2}{\text{O)]}}^\Theta }$

The Henry's law constant $\left(\mathrm{K}_H\right)$ values of three gases $(A, B, C)$ in water are $145,2 \times 10^{-5}$ and $35$ kbar, respectively. The solubility of these gases in water follow the order: