Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R): 
Assertion (A): A reaction can have zero activation energy.
Reason (R): The minimum extra amount of energy absorbed by reactant molecules so that their
energy becomes equal to threshold value, is called activation energy. 
In the light of the above statements choose the correct answer from the options given below:
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. (A) is false but (R) is true.
Subtopic:  Arrhenius Equation |
From NCERT
NEET - 2023
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The plot of ln k vs \({1 \over T}\) for the following reaction 
\(2N_2O_5(g) \rightarrow 4NO_2 (g) + O_2(g) \) gives a straight line with the slope of the line equal to \(-1.0 \times 10^4 K \). The activation energy for the reaction in J mol-1 is:
(Given R = 8.3 J K-1 mol-1)
1. \(4.0 \times 10^2 \)
2. \(4.0 \times 10^{-2} \)
3. \(8.3 \times 10^{-4} \)
4. \(8.3 \times 10^4 \)

Subtopic:  Arrhenius Equation |
 74%
From NCERT
NEET - 2022
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NEET 2023 - Target Batch - Aryan Raj Singh
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For a reaction AB, enthalpy of reaction is -4.2 kJmol-1 and enthalpy of activation is 9.6 kJmol-1. The correct potential energy profile for the reaction is:

1. 2.
3. 4.
Subtopic:  Arrhenius Equation |
 70%
From NCERT
NEET - 2021
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The slope of Arrhenius Plot (ln k v/s 1T) of the first-order reaction is -5×103 K. The value of Ea of the reaction is:

[Given R = 8.314 JK-1 mol-1]

1. 166 kJ mol-1 2. -83 kJ mol-1
3. 41.5 kJ mol-1 4. 83.0 kJ mol-1
Subtopic:  Arrhenius Equation |
 71%
From NCERT
NEET - 2021
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NEET 2023 - Target Batch - Aryan Raj Singh
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An increase in the concentration of the reactants of a reaction leads to a change in:

1. heat of reaction

2. threshold energy

3. collision frequency

4. activation energy

Subtopic:  Arrhenius Equation |
 63%
From NCERT
NEET - 2020
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What does ZAB represent in the collision theory of chemical reactions?

1. The fraction of molecules with energies greater than Ea

2. The collision frequency of reactants, A and B

3. Steric factor

4. The fraction of molecules with energies equal to Ea

Subtopic:  Arrhenius Equation |
 69%
From NCERT
NEET - 2020
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For a reaction, activation energy Ea=0 and the rate constant at 200 K is    1.6 X 106s-1. The rate constant at 400K will be [Given that gas constant, R=8.314 J K-1 mol-1]

1.  3. 2 x 104 s-1
2. 1.6 x 106s-1

3. 1.6 x103 s-1

4. 3.2 x 106 s-1

Subtopic:  Arrhenius Equation |
 76%
From NCERT
NEET - 2019
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NEET 2023 - Target Batch - Aryan Raj Singh
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