The reaction

Consider the following compounds

A device that converts energy of combustion of fuels
like hydrogen and methane, directly into electrical
energy is known as :-

In which of the following compounds, then C - Cl
bond ionisation shall give most stable carbonium ion?

The number of d-electrons in Fe²+ (Z = 26) is not
equal to the number of electrons in which one of
the following?

If the value of an equilibrium constant for a particular reaction is 1.6 × 10¹², then at equilibrium the system will contain :-