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. | \(36^{\circ} \mathrm{C}\) |
For the reaction 2N2O5(g) → 4NO2(g) + O2(g)the concentration of increases by 2.4 × 10-2 mol L-1
in 6 seconds. The rate of appearance of and the rate of disappearance of , 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
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.
For the reaction, C2H5I + OH- → C2H5OH + I- the rate constant was found to have a value of 5.03 × 10-2 moI-1 dm3 s-1 at 289 K and 6.71 mol-1 dm3 s-1 at 333 K.
The rate constant at 305 K will be:
The first order rate constant for a certain reaction increases from\(1.667 \times 10^{-6} \mathrm{~s}^{-1} \text { at } 727^{\circ} \mathrm{C} \text { to } 1.667 \times 10^{-4} \mathrm{~s}^{-1} \text { at } 1571{ }^{\circ} \mathrm{C}.\) The rate constant at \(1150^{\circ} \mathrm{C}\) is:
(assume activation energy is constant over the given temperature range)
1. | \(3.911 \times 10^{-5} \mathrm{~s}^{-1} \) | 2. | \(1 .139 \times 10^{-5} \mathrm{~s}^{-1} \) |
3. | \(3.318 \times 10^{-5} s^{-1} \) | 4. | \(1.193 \times 10^{-5} \mathrm{~s}^{-1}\) |
The thermal decomposition of a compound is of first order. If 50 % of a sample of the compound decomposes in 120 minutes, how long will it take for 90 % of the compound to decompose?
1. 399 min
2. 410 min
3. 250 min
4. 120 min
The half-life for radioactive decay of is 5730 y. An archaeological artifact containing wood had only 80 % of the found in a living tree. The age of the sample will be:
1. 1657.3 y
2. 1845.4 y
3. 1512.4 y
4. 1413.1 y
The following data were obtained during the first-order thermal decomposition of at a constant volume.
SO2Cl2(g) → SO2(g) + Cl2(g)
Experiment | Time/s | Total pressure/atm |
1 | 0 | 0.5 |
2 | 100 | 0.6 |
The rate of the reaction when total pressure is 0.65 atm will be:
1.
2.
3.
4.
At 400 K, the energy of activation of a reaction is decreased by 0.8 kcal in the presence of a catalyst. As a result, the rate will be:
1. | Increased by 2.71 times. | 2. | Increased by 1.18 times. |
3. | Decreased by 2.72 times. | 4. | Increased by 6.26 times. |
If of a reaction is 100 kJ mol-1, then the activation energy for the forward reaction must be
1. Greater than 100 kJ mol-1
2. Less than 100 kJ mol-1
3. Equal to 100 kJ mol-1
4. None of the above.