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

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

How many gram of cobalt metal will be deposited when a solution of cobalt (II) chloride is electrolyzed with a current of 10 amperes for 109 minutes (1 Faraday = 96,500 C; Atomic mass of Co = 59 u)

A button cell used in watches function as following.
Zn_(s) + Ag₂O_(s) + H₂O_(l) $$\rightleftharpoons$$ 2Ag_(s) + Zn²⁺_(aq) + 2OH^$$-$$_(aq)

If half cell potentials are
Zn²⁺_(aq) + 2e^$$-$$ $$ \to $$ Zn_(s);  E^o = $$-$$0.76 V
Ag₂O_(s) + H₂O_(l) + 2e^$$-$$ $$ \to $$ 2Ag_(s) + 2OH^$$-$$_(aq), E^o = 0.34 V

The cell potential will be