Which of the following statements is not true for the rate constant, k?
 
1. large value of k indicates fast reactions.
2. The value of k is independent of the concentration of reactants
3. The value of k is independent of the concentration of products
4. The value of the rate constant, k, as the name suggests is always constant for a particular reaction at all temperatures.

 
Subtopic:  Arrhenius Equation |
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Assertion (A): For an endothermic reaction, the potential energy of the reactant is more than the potential energy of the product.
Reason (R): Reactant molecules before converting to product form an activated complex that has lower energy than reactants as well as the products.
 
 
1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true but (R) is not the correct explanation of (A).
3. (A) is true but (R) is false.
4. Both (A) and (R) are false.

 
Subtopic:  Arrhenius Equation |
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The rate of a reaction is decreased by 3.555 times when the temperature was changed from 40°C to 30°C. The activation energy (in kJ mol-1) of the reaction is:
(Take R=8.314 J mol-1 K-1 In 3.555=1.268)

1. 100 kJ/mol
2. 120 kJ/mol
3. 95 kJ/mol
4. 108 kJ/mol

Subtopic:  Arrhenius Equation |
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The rate constant, the activation energy and the Arrhenius parameter of a chemical reaction at \(25^{\circ}C\) are \(3\times10^{-4}~s^{-1},104.4~kJ~mol^{-1}\) and \(6\times10^{14}~s^{-1}\) respectively. The value of the rate constant as \(T\rightarrow\infty\) is

1.  \(2\times10^{18}~s^{-1}\)
2.  \(6\times10^{14}~s^{-1}\)
3.  \(\infty\)
4.  \(3.6\times10^{30}~s^{-1}\)
Subtopic:  Arrhenius Equation |
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The rate constants of a reaction at 500K is 0.02s–1 . The values of Ea is 18.230 kJ. The value of A is-

1. 1.61
2. 1.41
3. 1.81
4. 1.21


 
Subtopic:  Arrhenius Equation |
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