Following mechanism has been proposed for a reaction,

2A+B $\to$D+E

A+B$\to$ C+D    ...(Slow)

A+ C$\to$ E         ...(Fast)

The rate law expression for the reaction is:

1. r = K[A]²[B]

2. r=K[A][B]

3. r= K[A]²

4. r= K[A][C]

In gaseous reactions important for the understanding of the upper atmosphere H₂O and O react bimolecularly to form two OH radicals. $∆$H for this reaction is 72kJ at 500 K and E_a is 77 kJ mol^-1, then E_a for the bimolecular recombination of two OH radicals to form H₂O and O is:

1. 3 kJ mol^-1

2. 4 kJ mol^-1

3. 5 kJ mol^-1

4. 7 kJ mol^-1

For the reaction N₂ + 3H₂ $\to$ 2NH₃, the rate $\frac{\mathrm{d}\left[{\mathrm{NH}}_3\right]}{\mathrm{dt}}$= 2 x 10^-4 M s^-1 .Therefore, the rate $\frac{-\mathrm{d}\left[{\mathrm{N}}_2\right]}{\mathrm{dt}}$ is given as:

1. 10^-4 Ms^-1

2. 10⁴ Ms^-1

3. 10^-2 sM^-1

4. 10^-4 sM^-1

The rate of a reaction get doubles when the temperature changes from 7°C to 17°C. By what factor will it change for the temperature change from 17°C to 27°C?

1. 1.81

2. 1.71

3. 1.91

4. 1.76

When ethyl acetate was hydrolysed in pressure of 0.1 N HCl, the rate constant was found to be 5.40 x 10^-5 sec^-1 . But when 0.1 N H₂SO₄ was used for hydrolysis, the rate constant was found to be 6.25 X10^-5sec^-1. Thus, it may be concluded that:

1. H₂SO₄ is stronger than HCI

2. H₂SO₄ is weaker than HCl

3. H₂SO₄ and HCl both have the same strength

4. The data are not sufficient to compare the strength of H₂SO₄ and HCI