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

The weight of silver (at. wt. = 108) displaced by a quantity of electricity which displaces 5600 mL of O₂ at STP will be

When 0.1 mol MnO$$_4^{2 - }$$ is oxidised the quantity of electricity required to completely oxidise MnO$$_4^{2 - }$$ to MnO$$_4^ - $$ is

Consider the half-cell reduction reaction
Mn²⁺ + 2e^$$-$$ $$ \to $$ Mn, E^o = $$-$$1.18 V
Mn²⁺ $$ \to $$ Mn³⁺ + e^$$-$$, E^o = $$-$$ 1.51 V
The $$E$$^o for the reaction 3 Mn²⁺ $$ \to $$ Mn^o + 2Mn³⁺, and possibility of the forward reaction are respectively