Pick out the isoelectronic structure from the following :

$$\eqalign{ & \left( i \right)\,\,\,\,\,\,C{H_3}^ + \cr & \left( {ii} \right)\,\,\,\,{H_3}{O^ + } \cr & \left( {iii} \right)\,\,\,N{H_3} \cr & \left( {iv} \right)\,\,\,\,C{H_3}^ - \cr} $$

For a spontaneous reaction the ∆G , equilibrium constant (K) and $$E_{cell}^o$$ will be respectively

Aluminium oxide may be electrolysed at 1000^oC to furnish aluminium metal (Atomic mass = 27 amu; 1 Faraday = 96,500 Coulombs). The cathode reaction is Al³⁺ + 3e^- $$\to$$ Al^o To prepare 5.12 kg of aluminium metal by this method would require

The highest electrical conductivity of the following aqueous solutions is of :