The following data were obtained during the first-order thermal decomposition of $S{O}_{2}C{l}_2$ 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. $7.8$ $\times$ ${10}^{-4}$ $s^{-1}$ $atm.$                                  

2. $0.8$ $\times$ ${10}^{-4}$ $s^{-1}$ $atm.$

3. $2.4$ $\times$ ${10}^{-2}$ $s^{-1}$ $atm.$                                   

4. $6.1$ $\times$ ${10}^{-8}$ $s^{-1}$ $atm.$

Assertion : A lump of coal burns at a moderate rate in air while coal dust burns explosively.

Reason : Coal dust contains very fine particles of carbon.

Assertion : Liquid bromine reacts slowly as compared to bromine vapour.

Reason : In liquid bromine, the bromine molecules are held together by a force which is much weaker than the force existing between the two molecules of bromine in the vapour phase.

Assertion : The reaction,

$N_2<mspace\; width="1em"></mspace>\left(10atm\right)<mspace\; width="1em"></mspace>3H_2<mspace\; width="1em"></mspace>\left(10atm\right)\to <mspace\; width="1em"></mspace>2N{H}_3<mspace\; width="1em"></mspace>\left(g\right)<mspace\; width="1em"></mspace>is<mspace\; width="1em"></mspace>faster.$

Reason : Catalyst lowers the activation energy of the reaction.

Assertion : Molecularity of a reaction cannot be determined experimentally.

Reason : Molecularity is assigned to the reactions on the basis of mechanism.
 

Assertion : For a first order reaction, the degree of dissocation is equal to $\left(1-e^{-kt}\right)$

Reason  : For a first order reaction, the pre-exponential factor in the Arrhenius equation has the dimension of $tim{e}^{-1}$

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:

If $∆\mathrm{H}$ 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.

Calculate the time after which the concentrations of substances A and B become equal if [A₀] = 4[B₀]. Both undergo first-order decay with half-lives of 5 min and 15 min, respectively.

1.  15 minutes                                        

2.  10 minutes

3.  5 minutes                                          

4.  12 minutes

The half-life for radioactive decay of ${}^{14}C$ is 5730 y. An archaeological artifact containing wood had only 80 % of the ${}^{14}C$ 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