The following molecule acts as an :

Adsorption of a gas follows Freundlich adsorption isotherm. If x is the mass of the gas adsorbed on mass
m of the adsorbent, the correct plot of $${x \over m}$$ versus p is :

The compound that has the largest H–M–H bond angle (M = N, O, S, C) is :

The rate constant (k) of a reaction is measured at differenct temperatures (T), and the data are plotted in the given figure. The activation energy of the reaction in kJ mol^–1 is :
(R is gas constant)