The rate of a reaction becomes three times when the temperature is increased from 20 °C to 50 °C.
Calculate the activation energy of the reaction.

1. \(28.81 \mathrm{~kJ} \mathrm{~mol}^{-1} \) 2. \(38.51 \mathrm{~kJ} \mathrm{~mol}^{-1} \)
3. \(18.81 \mathrm{~kJ} \mathrm{~mol}^{-1} \) 4. \(8.31 \mathrm{~kJ} \mathrm{~mol}^{-1}\)

Subtopic:  Arrhenius Equation |
 64%
Level 2: 60%+
Hints
Links

The half-life time for the decomposition of a substance dissolved in CCl4 is 2.5 hours at \(30^{\circ} \mathrm{C}\) The amount of substance that will be left after 10 hours if the initial weight of the substance is 160 gm is:

1. 20 gm 2. 30 gm
3. 40 gm 4. 10 gm
Subtopic:  First Order Reaction Kinetics |
 75%
Level 2: 60%+
Hints
Links

Given the following reaction:
N2O5   as   N2O5   ⇌ 2NO2 + (1/2)O2
The values of rate constants for the above reaction are 3.45 × 10-5 and 6.9 × 10-3 at 27 oC and 67 oC respectively. The activation energy for the above reaction is : 

1. 102 ×102 J                                      

2. 488.5 kJ

3. 112 J                                              

4. 112.5 kJ

Subtopic:  Arrhenius Equation |
 63%
Level 2: 60%+
Hints
Links

advertisementadvertisement

What is the percentage of the reactant molecules crossing over the energy barrier at 325 K?

Given that H325=0.12 kcal, Eab=+0.02 kcal

1. 80.62 % 2. 85.23 %
3. 89.27 % 4. None of the above
Subtopic:  First Order Reaction Kinetics |
Level 3: 35%-60%
Hints

1 mole of a gas changes linearly from its initial state (2 atm, 10 lt) to its final state (8 atm, 4 lt). The maximum rate constant is equal to 20 sec-1 and the value of activation energy is 40 kJ, assuming that the activation energy does not change in this temperature range. The value of the rate constant, at the maximum temperature that the gas can attain, is: 

1. 0.56 × 10-3 sec-1                                          

2. 3.16 × 10-3 sec-1

3. 1.56 × 10-3sec-1                                          

4. 5.12 × 10-3 sec-1

Subtopic:  First Order Reaction Kinetics |
Level 3: 35%-60%
Hints

A first-order reaction is initiated with a 0.10 M solution of the reactant. After 8 minutes 20 seconds,
 the concentration decreases to 0.01 M. Calculate the rate constant of the reaction.

1.  4.6 × 10⁻³ s⁻¹
2. 16.6 × 10⁻³ s⁻¹
3.  24.6 × 10⁻³ s⁻¹
4.  40.6 × 10⁻³ s⁻¹

Subtopic:  First Order Reaction Kinetics |
 73%
Level 2: 60%+
Hints

advertisementadvertisement

The decomposition of A into product has value of k as \(4.5 \times 10^3 \mathrm{~s}^{-1} \text { at } 10^{\circ} \mathrm{C}.\) Energy of activation of the reaction is \(60 \mathrm{~kJ}~mol^{-1}.\) The temperature at which value k would become \(1.5\times10^4~s^{-1}\) is : 

1. \(12{ }^{\circ} \mathrm{C} \) 2. \(24^{\circ} \mathrm{C} \)
3. \(48^{\circ} \mathrm{C} \) 4. \(36^{\circ} \mathrm{C}\)
Subtopic:  Arrhenius Equation |
 61%
Level 2: 60%+
Hints
Links

For the reaction 2N2O5(g) → 4NO2(g) + O2(g), the concentration of  NO2 increases by 2.4 × 10-2 mol L-1

in 6 seconds. The rate of appearance of NO2 and the rate of disappearance of N2O5 , respectively, are:

1. 2 x 10-3 mol L-1 sec-1, 4 x 10-3 mol L-1 sec-1

2. 2 x 10-3 mol L-1 sec-1, 1 x 10-3 mol L-1 sec-1

3. 2 x 10-3 mol L-1 sec-1, 2 x 10-3 mol L-1 sec-1

4. 4 x 10-3 mol L-1 sec-1, 2 x 10-3 mol L-1 sec-1

Subtopic:  Definition, Rate Constant, Rate Law |
 65%
Level 2: 60%+
Hints
Links

The rate constant of a particular reaction has the dimension of frequency. The order of the reaction is: 

1. Zero.                                                     

2. First.

3. Second.                                                 

4. Fractional.

Subtopic:  Definition, Rate Constant, Rate Law |
 80%
Level 1: 80%+
Hints
Links

advertisementadvertisement

For the reaction, C2H5I + OH- → C2H5OH + I- the rate constant was found to have a value of 5.03 × 10-2 moI-1 dms-1 at 289 K and 6.71 mol-1 dm3 s-1 at 333 K. 

The rate constant at 305 K will be: 

1. 1.35 mol-1 dm3 s-1                  

2. 0.35 mol-1 dm3 s-1

3. 3.15 mol-1 dm3 s-1                    

4. 7.14 mol-1 dm3 s-1

Subtopic:  Arrhenius Equation |
 53%
Level 3: 35%-60%
Hints
Links