The activation energies of the forward and backward reactions in the case of a chemical reaction are 30.5 and 45.4 KJ/mol respectively. The reaction is
1. Exothermic
2. Endothermic
3. Neither exothermic nor endothermic
4. Independent of temperature
The t0.5 for the first order reaction.
PCl5(g) PCl3(g) + Cl2(g) is 20 min. The time in which the conc. of PCl5 reduces to 25% of the initial conc. is close to
1. 22 min
2. 40 min
3. 90 min
4. 50 min
Consider a reaction A + B → C. If the initial concentration of A was reduced from 4M to 2M in 1 hour and from 2M to 1M in 0.5 hours, the order of the reaction is
1. One
2. Zero
3. Two
4. Three
A gaseous reaction A2(g) → B(g) + (g) shows increase in pressure from 100 mm to 120 mm in 5 minutes. The rate of disappearance of A2 will be :
1. | 4 mm min-1 | 2. | 8 mm min-1 |
3. | 16 mm min-1 | 4. | 2 mm min-1 |
During the formation of ammonia by Haber's process N2 + 3H2 → 2NH3, the rate of appearance of NH3 was measured as 2.5 x 10-4 mol L-1 s-1. The rate of disappearance of H2 will be:
1. 2.5 x 10-4 mol L-1 s-1
2. 1.25 x 10-4 mol L-1 s-1
3. 3.75 x 10-4 mol L-1 s-1
4. 15.00 x 10-4 mol L-1 s-1
For a chemical reaction, A products, the rate of reaction doubles when the concentration of A is increased by 4 times. The order of the reaction is
1. 4
2. 0
3. 1/2
4. 1
The correct expression for the 3/4th life of a first-order reaction is:
From the plot of log k vs 1/T, following parameter can be calculated:
1. Activation energy.
2. Rate constant of reaction .
3. Order of reaction.
4. Activation energy as well as the frequency factor.
For an endothermic reaction, where ΔH represents the enthalpy of the reaction in kJ/mol, the minimum value for the energy of activation will be
1. Less than ΔH
2. Zero
3. More than ΔH
4. Equal to ΔΗ
In the formation or sulphur trioxide by the contact process,
2SO2(g) + O2(g) 2SO3(g)
The rate of reaction is expressed as = 2.5x10-4 mol L-1sec-1. The rate disappearance of SO2 will be
1. 5.0x10-4 mol L-1sec-1
2. 2.5x10-4 mol L-1sec-1
3. 3.75x10-4 mol L-1sec-1
4. 50.0x10-4 mol L-1sec-1