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. |
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. |
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. \(8.3 \times 10^4 \)
For a reaction AB, enthalpy of reaction is and enthalpy of activation is . The correct potential energy profile for the reaction is:
1. | 2. | ||
3. | 4. |
The slope of Arrhenius Plot (ln k v/s ) of the first-order reaction is . 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 |
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
For a reaction, activation energy and the rate constant at 200 K is 1.6 . The rate constant at 400K will be [Given that gas constant, R=8.314 J ]
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
A reaction having equal energies of activation for forward and reverse reaction has:
1. ΔG = 0
2. ΔH = 0
3. ΔH = ΔG = ΔS = 0
4. ΔS = 0
For an endothermic reaction, the energy of activation is Ea, and the enthalpy of reaction is ΔH (both of these in kJ/mol). The minimum value of Ea will be:
1. Less than H
2. Equal to H
3. More than H
4. Equal to zero