If the rate constant for a first order reaction is k, the time (t) required for the completion of 99% of the reaction is given by:
1. t = 2.303/k
2. t = 0.693/k
3. t = 6.909/k
4. t = 4.606/k
For the chemical reaction the correct option is:
1. | 2. | ||
3. | 4. |
A first-order reaction has a rate constant of 2.303 . The time required for 40 g of this reactant to reduce to 10 g will be
[Given that ]
1. | 230.3 s | 2. | 301 s |
3. | 2000 s | 4. | 602 s |
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 × 104 s-1
2. 1.6 × 106s-1
3. 1.6 × 103 s-1
4. 3.2 × 106 s-1
The rate constant for a first order reaction is . The time required to reduce 2.0 g of the reactant to 0.2 g is:
1. | 200 s | 2. | 500 s |
3. | 1000 s | 4. | 100 s |
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 |
The half-life for a zero-order reaction having 0.02 M initial concentration of reactant is 100 s. The rate constant (in mol L–1 s–1) for the reaction is:
1.
2.
3.
4.
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 |
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 |