Consider the following data.

(i) $2\text{Al(s)} + 6\text{HCl(aq)} \rightarrow \text{Al}_2\text{Cl}_6\text{(aq)} + 3\text{H}_2\text{(g)} + 1200~\text{kJ/mol}$

(ii) $\text{H}_2\text{(g)} + \text{Cl}_2\text{(g)} \rightarrow 2\text{HCl(g)} + 164~\text{kJ/mol}$

(iii) $\text{HCl(g)} + \text{aq} \rightarrow \text{HCl(aq)} + 83~\text{kJ/mol}$

(iv) $\text{Al}_2\text{Cl}_6\text{(s)} + \text{aq} \rightarrow \text{Al}_2\text{Cl}_6\text{(aq)} + 663~\text{kJ/mol}$

The enthalpy of formation of anhydrous solid $\text{Al}_2\text{Cl}_6$ is :

The plot of $\log_{10} K$ vs $\frac{1}{T}$ gives a straight line. The intercept and slope respectively are (where K is equilibrium constant).

$20.0 \mathrm{dm}^3$ of an ideal gas ' X ' at 600 K and 0.5 MPa undergoes isothermal reversible expansion until pressure of the gas is 0.2 MPa . Which of the following option is correct?

(Given: $\log 2=0.3010$ and $\log 5=0.6989$ )

The heat of atomisation of methane and ethane are ' x ' $\mathrm{kJ} \mathrm{mol}^{-1}$ and ' y ' $\mathrm{kJ} \mathrm{mol}^{-1}$ respectively. The longest wavelength ( $\lambda$ ) of light capable of breaking the $\mathrm{C}-\mathrm{C}$ bond can be expressed in SI unit as :