An oxide of metal (at . Wt = 112) contains 12.5% of oxygen by weight. What is the valency of metal? What mass of the metal will be liberated when the oxide is converted to chloride with HCl and electrolysed using a current of 9.65 amp for a period of 30 min?

Explanation

Equivalent of oxygen `=` Equivalent of metal
`(12.5)/(8) = (87.5)/(E)`,
where E is the equivalent weight of metal, `E=56`.
Valency of metal `=` At. wt./Eq. wt. `=112//56=2`
Mass of the metal deposited `=(E xx i xx t)/(96500)`
Substituting the values `=(56xx9.65xx30xx60)/(96500)`
Mass of metal `=10.08` g