The magnitude of work done by a gas that undergoes a reversible expansion along the path ABC shown in the figure is _______.

The first ionization energy (in kJ/mol) of Na, Mg, Al and Si respectively, are :

The decreasing order of reactivity towards dehydrohalogenation (E₁) reaction of the following compounds is :

The strength of an aqueous NaOH solution is most accurately determined by titrating :
(Note : consider that an appropriate indicator is used)