Molar ionic conductivities of divalent cation and anion are $$57 \mathrm{~S~cm}^2 \mathrm{~mol}^{-1}$$ and $$73 \mathrm{~S~cm}^2 \mathrm{~mol}^{-1}$$ respectively. The molar conductivity of solution of an electrolyte with the above cation and anion will be:

The reaction at cathode in the cells commonly used in clocks involves.

Fuel cell, using hydrogen and oxygen as fuels,

A. has been used in spaceship

B. has as efficiency of $$40 \%$$ to produce electricity

C. uses aluminum as catalysts

D. is eco-friendly

E. is actually a type of Galvanic cell only

Choose the correct answer from the options given below:

For a strong electrolyte, a plot of molar conductivity against (concentration) $${ }^{1 / 2}$$ is a straight line, with a negative slope, the correct unit for the slope is