Molecularity and Mechanism of a Reaction
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CHXII04:CHEMICAL KINETICS

320526 A hypothetical reaction, \({{\rm{A}}_{\rm{2}}}{\rm{ + }}{{\rm{B}}_{\rm{2}}} \to {\rm{2AB}}\) follows the mechanism as given below:
\({{\text{A}}_{\text{2}}}\mathop \rightleftharpoons \limits^{\text{K}} {\text{A + A( fast )}}\)
\({\rm{A + }}{{\rm{B}}_{\rm{2}}} \to {\rm{AB + B}}\,\,{\rm{(slow)}}\)
\({\rm{A + B}} \to {\rm{AB}}\,\,{\rm{(fast)}}\)
The order of the overall reaction is:

1 2
2 1
3 \(1 \dfrac{1}{2}\)
4 Zero
CHXII04:CHEMICAL KINETICS

320527 Which of the following is the correct statement?

1 Order of a reaction has always an integral value
2 Mechanism of a reaction proposed is always final
3 Zero order reactions are multi step reactions
4 Order of reaction can be predicted even without knowing the rate law
CHXII04:CHEMICAL KINETICS

320528 In the sequence of reaction
\({\text{A}}\xrightarrow{{{{\text{k}}_{\text{1}}}}}{\text{ B}}\xrightarrow{{{{\text{k}}_{\text{2}}}}}{\text{C}}\xrightarrow{{{{\text{k}}_{\text{3}}}}}{\text{D; }}{{\text{k}}_{\text{3}}}{\text{ > }}{{\text{k}}_{\text{2}}}{\text{ > }}{{\text{k}}_{\text{1}}}\)
Then the rate determining step of the reaction is

1 \(\mathrm{A} \rightarrow \mathrm{B}\)
2 \(\mathrm{C} \rightarrow \mathrm{D}\)
3 \(\mathrm{B} \rightarrow \mathrm{C}\)
4 \(\mathrm{A} \rightarrow \mathrm{D}\)
CHXII04:CHEMICAL KINETICS

320529 The reaction \(2 \mathrm{HI} \rightarrow \mathrm{H}_{2}+\mathrm{I}_{2}\) follows first order kinetics. Hence, the molecularity of the reaction is

1 Unimolecular
2 Pseudo unimolecular
3 Bimolecular
4 None of the above
CHXII04:CHEMICAL KINETICS

320530 Rate of the given reaction,
\({\text{ I}}{\text{. A}} + {\text{B}}\xrightarrow{{{r_1} = 0.05}}{\text{X}}\)
\({\text{II}}.\,\,{\text{X}} + {\text{B}}\xrightarrow{{{r_2} = 0.89}}{\text{Y}}\)
\({\text{III}}.\,\,{\text{Y}} + {\text{A}}\xrightarrow{{{r_3} = 0.001}}{\text{(AY)}}\)
\({\text{IV}}{\text{.}}\,\,{\text{AY}} + {\text{B}}\xrightarrow{{{r_4} = 0.10}}{\text{AYB}}\)
will be determined by

1 step I : because the reaction starts with the formation of \({\text{X}}\)
2 step II : because it is the fastest step
3 step III : because it is the slowest step
4 step IV : because it ends the reaction
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CHXII04:CHEMICAL KINETICS

320526 A hypothetical reaction, \({{\rm{A}}_{\rm{2}}}{\rm{ + }}{{\rm{B}}_{\rm{2}}} \to {\rm{2AB}}\) follows the mechanism as given below:
\({{\text{A}}_{\text{2}}}\mathop \rightleftharpoons \limits^{\text{K}} {\text{A + A( fast )}}\)
\({\rm{A + }}{{\rm{B}}_{\rm{2}}} \to {\rm{AB + B}}\,\,{\rm{(slow)}}\)
\({\rm{A + B}} \to {\rm{AB}}\,\,{\rm{(fast)}}\)
The order of the overall reaction is:

1 2
2 1
3 \(1 \dfrac{1}{2}\)
4 Zero
CHXII04:CHEMICAL KINETICS

320527 Which of the following is the correct statement?

1 Order of a reaction has always an integral value
2 Mechanism of a reaction proposed is always final
3 Zero order reactions are multi step reactions
4 Order of reaction can be predicted even without knowing the rate law
CHXII04:CHEMICAL KINETICS

320528 In the sequence of reaction
\({\text{A}}\xrightarrow{{{{\text{k}}_{\text{1}}}}}{\text{ B}}\xrightarrow{{{{\text{k}}_{\text{2}}}}}{\text{C}}\xrightarrow{{{{\text{k}}_{\text{3}}}}}{\text{D; }}{{\text{k}}_{\text{3}}}{\text{ > }}{{\text{k}}_{\text{2}}}{\text{ > }}{{\text{k}}_{\text{1}}}\)
Then the rate determining step of the reaction is

1 \(\mathrm{A} \rightarrow \mathrm{B}\)
2 \(\mathrm{C} \rightarrow \mathrm{D}\)
3 \(\mathrm{B} \rightarrow \mathrm{C}\)
4 \(\mathrm{A} \rightarrow \mathrm{D}\)
CHXII04:CHEMICAL KINETICS

320529 The reaction \(2 \mathrm{HI} \rightarrow \mathrm{H}_{2}+\mathrm{I}_{2}\) follows first order kinetics. Hence, the molecularity of the reaction is

1 Unimolecular
2 Pseudo unimolecular
3 Bimolecular
4 None of the above
CHXII04:CHEMICAL KINETICS

320530 Rate of the given reaction,
\({\text{ I}}{\text{. A}} + {\text{B}}\xrightarrow{{{r_1} = 0.05}}{\text{X}}\)
\({\text{II}}.\,\,{\text{X}} + {\text{B}}\xrightarrow{{{r_2} = 0.89}}{\text{Y}}\)
\({\text{III}}.\,\,{\text{Y}} + {\text{A}}\xrightarrow{{{r_3} = 0.001}}{\text{(AY)}}\)
\({\text{IV}}{\text{.}}\,\,{\text{AY}} + {\text{B}}\xrightarrow{{{r_4} = 0.10}}{\text{AYB}}\)
will be determined by

1 step I : because the reaction starts with the formation of \({\text{X}}\)
2 step II : because it is the fastest step
3 step III : because it is the slowest step
4 step IV : because it ends the reaction
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CHXII04:CHEMICAL KINETICS

320526 A hypothetical reaction, \({{\rm{A}}_{\rm{2}}}{\rm{ + }}{{\rm{B}}_{\rm{2}}} \to {\rm{2AB}}\) follows the mechanism as given below:
\({{\text{A}}_{\text{2}}}\mathop \rightleftharpoons \limits^{\text{K}} {\text{A + A( fast )}}\)
\({\rm{A + }}{{\rm{B}}_{\rm{2}}} \to {\rm{AB + B}}\,\,{\rm{(slow)}}\)
\({\rm{A + B}} \to {\rm{AB}}\,\,{\rm{(fast)}}\)
The order of the overall reaction is:

1 2
2 1
3 \(1 \dfrac{1}{2}\)
4 Zero
CHXII04:CHEMICAL KINETICS

320527 Which of the following is the correct statement?

1 Order of a reaction has always an integral value
2 Mechanism of a reaction proposed is always final
3 Zero order reactions are multi step reactions
4 Order of reaction can be predicted even without knowing the rate law
CHXII04:CHEMICAL KINETICS

320528 In the sequence of reaction
\({\text{A}}\xrightarrow{{{{\text{k}}_{\text{1}}}}}{\text{ B}}\xrightarrow{{{{\text{k}}_{\text{2}}}}}{\text{C}}\xrightarrow{{{{\text{k}}_{\text{3}}}}}{\text{D; }}{{\text{k}}_{\text{3}}}{\text{ > }}{{\text{k}}_{\text{2}}}{\text{ > }}{{\text{k}}_{\text{1}}}\)
Then the rate determining step of the reaction is

1 \(\mathrm{A} \rightarrow \mathrm{B}\)
2 \(\mathrm{C} \rightarrow \mathrm{D}\)
3 \(\mathrm{B} \rightarrow \mathrm{C}\)
4 \(\mathrm{A} \rightarrow \mathrm{D}\)
CHXII04:CHEMICAL KINETICS

320529 The reaction \(2 \mathrm{HI} \rightarrow \mathrm{H}_{2}+\mathrm{I}_{2}\) follows first order kinetics. Hence, the molecularity of the reaction is

1 Unimolecular
2 Pseudo unimolecular
3 Bimolecular
4 None of the above
CHXII04:CHEMICAL KINETICS

320530 Rate of the given reaction,
\({\text{ I}}{\text{. A}} + {\text{B}}\xrightarrow{{{r_1} = 0.05}}{\text{X}}\)
\({\text{II}}.\,\,{\text{X}} + {\text{B}}\xrightarrow{{{r_2} = 0.89}}{\text{Y}}\)
\({\text{III}}.\,\,{\text{Y}} + {\text{A}}\xrightarrow{{{r_3} = 0.001}}{\text{(AY)}}\)
\({\text{IV}}{\text{.}}\,\,{\text{AY}} + {\text{B}}\xrightarrow{{{r_4} = 0.10}}{\text{AYB}}\)
will be determined by

1 step I : because the reaction starts with the formation of \({\text{X}}\)
2 step II : because it is the fastest step
3 step III : because it is the slowest step
4 step IV : because it ends the reaction
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CHXII04:CHEMICAL KINETICS

320526 A hypothetical reaction, \({{\rm{A}}_{\rm{2}}}{\rm{ + }}{{\rm{B}}_{\rm{2}}} \to {\rm{2AB}}\) follows the mechanism as given below:
\({{\text{A}}_{\text{2}}}\mathop \rightleftharpoons \limits^{\text{K}} {\text{A + A( fast )}}\)
\({\rm{A + }}{{\rm{B}}_{\rm{2}}} \to {\rm{AB + B}}\,\,{\rm{(slow)}}\)
\({\rm{A + B}} \to {\rm{AB}}\,\,{\rm{(fast)}}\)
The order of the overall reaction is:

1 2
2 1
3 \(1 \dfrac{1}{2}\)
4 Zero
CHXII04:CHEMICAL KINETICS

320527 Which of the following is the correct statement?

1 Order of a reaction has always an integral value
2 Mechanism of a reaction proposed is always final
3 Zero order reactions are multi step reactions
4 Order of reaction can be predicted even without knowing the rate law
CHXII04:CHEMICAL KINETICS

320528 In the sequence of reaction
\({\text{A}}\xrightarrow{{{{\text{k}}_{\text{1}}}}}{\text{ B}}\xrightarrow{{{{\text{k}}_{\text{2}}}}}{\text{C}}\xrightarrow{{{{\text{k}}_{\text{3}}}}}{\text{D; }}{{\text{k}}_{\text{3}}}{\text{ > }}{{\text{k}}_{\text{2}}}{\text{ > }}{{\text{k}}_{\text{1}}}\)
Then the rate determining step of the reaction is

1 \(\mathrm{A} \rightarrow \mathrm{B}\)
2 \(\mathrm{C} \rightarrow \mathrm{D}\)
3 \(\mathrm{B} \rightarrow \mathrm{C}\)
4 \(\mathrm{A} \rightarrow \mathrm{D}\)
CHXII04:CHEMICAL KINETICS

320529 The reaction \(2 \mathrm{HI} \rightarrow \mathrm{H}_{2}+\mathrm{I}_{2}\) follows first order kinetics. Hence, the molecularity of the reaction is

1 Unimolecular
2 Pseudo unimolecular
3 Bimolecular
4 None of the above
CHXII04:CHEMICAL KINETICS

320530 Rate of the given reaction,
\({\text{ I}}{\text{. A}} + {\text{B}}\xrightarrow{{{r_1} = 0.05}}{\text{X}}\)
\({\text{II}}.\,\,{\text{X}} + {\text{B}}\xrightarrow{{{r_2} = 0.89}}{\text{Y}}\)
\({\text{III}}.\,\,{\text{Y}} + {\text{A}}\xrightarrow{{{r_3} = 0.001}}{\text{(AY)}}\)
\({\text{IV}}{\text{.}}\,\,{\text{AY}} + {\text{B}}\xrightarrow{{{r_4} = 0.10}}{\text{AYB}}\)
will be determined by

1 step I : because the reaction starts with the formation of \({\text{X}}\)
2 step II : because it is the fastest step
3 step III : because it is the slowest step
4 step IV : because it ends the reaction
NEET DIGITAL LIBRARY
CHXII04:CHEMICAL KINETICS

320526 A hypothetical reaction, \({{\rm{A}}_{\rm{2}}}{\rm{ + }}{{\rm{B}}_{\rm{2}}} \to {\rm{2AB}}\) follows the mechanism as given below:
\({{\text{A}}_{\text{2}}}\mathop \rightleftharpoons \limits^{\text{K}} {\text{A + A( fast )}}\)
\({\rm{A + }}{{\rm{B}}_{\rm{2}}} \to {\rm{AB + B}}\,\,{\rm{(slow)}}\)
\({\rm{A + B}} \to {\rm{AB}}\,\,{\rm{(fast)}}\)
The order of the overall reaction is:

1 2
2 1
3 \(1 \dfrac{1}{2}\)
4 Zero
CHXII04:CHEMICAL KINETICS

320527 Which of the following is the correct statement?

1 Order of a reaction has always an integral value
2 Mechanism of a reaction proposed is always final
3 Zero order reactions are multi step reactions
4 Order of reaction can be predicted even without knowing the rate law
CHXII04:CHEMICAL KINETICS

320528 In the sequence of reaction
\({\text{A}}\xrightarrow{{{{\text{k}}_{\text{1}}}}}{\text{ B}}\xrightarrow{{{{\text{k}}_{\text{2}}}}}{\text{C}}\xrightarrow{{{{\text{k}}_{\text{3}}}}}{\text{D; }}{{\text{k}}_{\text{3}}}{\text{ > }}{{\text{k}}_{\text{2}}}{\text{ > }}{{\text{k}}_{\text{1}}}\)
Then the rate determining step of the reaction is

1 \(\mathrm{A} \rightarrow \mathrm{B}\)
2 \(\mathrm{C} \rightarrow \mathrm{D}\)
3 \(\mathrm{B} \rightarrow \mathrm{C}\)
4 \(\mathrm{A} \rightarrow \mathrm{D}\)
CHXII04:CHEMICAL KINETICS

320529 The reaction \(2 \mathrm{HI} \rightarrow \mathrm{H}_{2}+\mathrm{I}_{2}\) follows first order kinetics. Hence, the molecularity of the reaction is

1 Unimolecular
2 Pseudo unimolecular
3 Bimolecular
4 None of the above
CHXII04:CHEMICAL KINETICS

320530 Rate of the given reaction,
\({\text{ I}}{\text{. A}} + {\text{B}}\xrightarrow{{{r_1} = 0.05}}{\text{X}}\)
\({\text{II}}.\,\,{\text{X}} + {\text{B}}\xrightarrow{{{r_2} = 0.89}}{\text{Y}}\)
\({\text{III}}.\,\,{\text{Y}} + {\text{A}}\xrightarrow{{{r_3} = 0.001}}{\text{(AY)}}\)
\({\text{IV}}{\text{.}}\,\,{\text{AY}} + {\text{B}}\xrightarrow{{{r_4} = 0.10}}{\text{AYB}}\)
will be determined by

1 step I : because the reaction starts with the formation of \({\text{X}}\)
2 step II : because it is the fastest step
3 step III : because it is the slowest step
4 step IV : because it ends the reaction