Given below are the half-cell reactions:

Mn²⁺ + 2e^- $$\to$$ Mn; E^o = -1.18 V

2(Mn³⁺ + e^- $$\to$$ Mn²⁺); E^o = +1.51 V

The E^o for 3Mn²⁺ $$\to$$ Mn + 2Mn³⁺ will be :

The correct set of four quantum numbers for the valence elections of rubidium atom (Z= 37) is:

The variance of first 50 even natural numbers is

$$\mathop {\lim }\limits_{x \to 0} {{\sin \left( {\pi {{\cos }^2}x} \right)} \over {{x^2}}}$$ is equal to :