The incorrect statement among the following is :

Which one of the following is an oxide?

To find the standard potential of M³⁺/M electrode,the following cell is constituted : Pt/M/M³⁺(0.001 mol L⁻¹ )/Ag⁺(0.01 mol L⁻¹ )/Ag

The emf of the cell is found to be 0.421 volt at 298 K. The standard potential of half reaction M3⁺ + 3e⁻$$ \to $$ M at 298 K will be :

(Given $$E_{A{g^ + }\,/\,Ag}^ - $$ at 298 K = 0.80 Volt)

An ideal gas undergoes isothermal expansion at constant pressure. During the process :