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प्रश्न
Assertion: The enthalpy of reaction remains constant in the presence of a catalyst.
Reason: A catalyst participating in the reaction, forms different activated complex and lowers down the activation energy but the difference in energy of reactant and product remains the same.
पर्याय
Both assertion and reason are correct and the reason is correct explanation of assertion.
Both assertion and reason are correct but reason does not explain assertion.
Assertion is correct but reason is incorrect.
Both assertion and reason are incorrect.
Assertion is incorrect but reason is correct.
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उत्तर
Both assertion and reason are correct and the reason is correct explanation of assertion.
Explanation:
AH = Activation Energy of forward reaction – Activation Energy of reverse reaction.
Catalyst does not alter heat of reaction because it affects activation energy of forward and reverse reactions equally.
APPEARS IN
संबंधित प्रश्न
Define “zero order reaction”.
What is pseudo first order reaction? Give one· example of it.
Write molecularity of the following reaction:
2NO(g)+O2(g)→2NO2(g)
For a reaction: 
Rate = k
(i) Write the order and molecularity of this reaction.
(ii) Write the unit of k.
The following data were obtained during the first order thermal decomposition of SO2Cl2 at a constant volume :
SO2Cl2 (g) → SO2 (g) + Cl2 (g)
| Experiment | Time/s–1 | Total pressure/atm |
| 1 | 0 | 0.4 |
| 2 | 100 | 0.7 |
Calculate the rate constant.
(Given : log 4 = 0.6021, log 2 = 0.3010)
The conversion of molecules X to Y follows second order kinetics. If concentration of X is increased to three times how will it affect the rate of formation of Y?
From the rate expression for the following reaction, determine the order of reaction and the dimension of the rate constant.
\[\ce{C2H5Cl_{(g)} -> C2H4_{(g)} + HCl_{(g)}}\] Rate = k [C2H5Cl]
A reaction is first order in A and second order in B. How is the rate affected when the concentrations of both A and B are doubled?
Write resonating structures of ozone.
Consider the reaction A ⇌ B. The concentration of both the reactants and the products varies exponentially with time. Which of the following figures correctly describes the change in concentration of reactants and products with time?
Match the graph given in Column I with the order of reaction given in Column II. More than one item in Column I may link to the same item of Column II.
| Column I | Column II | |
| (i) | ![]() |
|
| (ii) | ![]() |
(a) 1st order |
| (iii) | ![]() |
(b) Zero-order |
| (iv) | ![]() |
Assertion: Order of the reaction can be zero or fractional.
Reason: We cannot determine order from balanced chemical equation.
Assertion: Rate constants determined from Arrhenius equation are fairly accurate for simple as well as complex molecules.
Reason: Reactant molecules undergo chemical change irrespective of their orientation during collision.
The role of a catalyst is to change
For a reaction \[\ce{Cl2l(g) + 2No(g) -> 2NaCl(g)}\] the rate law is expressed as rate= K[Cl2] [No]2 what is the order of the reaction?
A drop of solution (volume 0.05 ml) contains 3.0 × 10-6 mole of H+. If the rate constant of disappearance of H+ is 1.0 × 107 mole l-1s-1. It would take for H+ in drop to disappear in ______ × 10-9s.
A flask contains a mixture of compounds A and B. Both compounds decompose by first-order kinetics. The half-lives for A and B are 300 s and 180 s, respectively. If the concentrations of A and B are equal initially, the time required for the concentration of A to be four times that of B (in s) is ______. (Use ln 2 = 0.693)
Assertion (A): Order of reaction is applicable to elementary as well as complex reactions.
Reason (R): For a complex reaction, molecularity has no meaning.




