In an estimation of sulphur by Carius method 0.2 g of the substance gave 0.6 g of $\mathrm{BaSO}_4$. The percentage of sulphur in the substance is $\_\_\_\_$%.

(Given molar mass in $\mathrm{g} \mathrm{mol}^{-1} \mathrm{~S}: 32, \mathrm{BaSO}_4: 231$ )

One mole of phenol is treated with dilute $\mathrm{HNO}_3$ at 298 K to give a mixture of products. The mixture is separated by steam distillation. The steam volatile compound $(\mathrm{X})$ is separated. The increase in percentage of oxygen in $(\mathrm{X})$ with respect to phenol is $\_\_\_\_$ $\times 10^{-1} \%$

(Given molar mass in $\mathrm{g} \mathrm{mol}^{-1} \mathrm{H}: 1, \mathrm{C}: 12, \mathrm{~N}: 14, \mathrm{O}: 16$ )

The values of pressure equilibrium constant recorded at different temperatures for the following equilibrium reaction have been given below $\mathrm{A}(\mathrm{g}) \rightleftharpoons \mathrm{B}(\mathrm{g})+\mathrm{C}(\mathrm{g})$

$$ \begin{array}{|c|c|} \hline \frac{1}{\mathrm{~T}}\left(\mathrm{~K}^{-1}\right) & \log _{10} \mathrm{~K}_{\mathrm{p}} \\ \hline 0.05 & 3.5 \\ \hline 0.06 & 2.5 \\ \hline 0.07 & 1.5 \\ \hline \end{array} $$

The magnitude of $\frac{\Delta \mathrm{H}^{\circ}}{\mathrm{R}}$ calculated from the above data is $\_\_\_\_$ . (Nearest integer)

If the half life of a first order reaction is 6.93 minutes then the time required for completion of $99 \%$ of the reaction will be $\_\_\_\_$ minutes.

(Given $: \log 2=0.3010$ )