A metal forms the fluoride MF3. Electrolysis of the molten fluoride by a current of 3.86 A for 16.2 minutes deposits 1.25 g of the metal. Calculate the molar mass of the metal.

The molar mass of the metal is 96.45 g/mol

Explanation:

The fluoride of the metal formed is

The oxidation half-reaction follows:

Calculating the theoretical mass deposited by using Faraday's law, which is:

      ......(1)

where,

m = actual mass deposited = 1.25 g

M = molar mass of metal = ?

I = average current = 3.86 A

t = time period in seconds = 16.2 min = 972 s            (Conversion factor: 1 min = 60 sec)

n = number of electrons exchanged =

F = Faraday's constant = 96500 C

Putting values in equation 1, we get:

Hence, the molar mass of the metal is 96.45 g/mol