To find the molar mass of the metal, we need to know the amount of moles of the metal deposited during electrolysis.
Given:
Current = 6.50A
Time = 1000s
Mass of metal deposited = 1.56g
First, let's calculate the charge passed through the electrolyte using Faraday's law of electrolysis.
Q = It
Q = 6.50A * 1000s
Q = 6500 C (Coulombs)
Next, let's calculate the moles of electrons passed using Faraday's law of electrolysis.
1F (Faraday) = 96485 C
Moles of electrons passed = Q / 1F
Moles of electrons passed = 6500 C / 96485 C/mol
Moles of electrons passed = 0.0674 mol
Since each metal ion is reduced through the gain of three electrons (M3+ + 3e- -> M), the moles of metal deposited is one-third of the moles of electrons passed.
Moles of metal = 0.0674 mol / 3
Moles of metal = 0.0225 mol
Finally, we can calculate the molar mass of the metal using the formula:
Molar mass (g/mol) = Mass of metal deposited (g) / Moles of metal
Molar mass = 1.56g / 0.0225 mol
Molar mass ≈ 69.3 g/mol
Therefore, the molar mass of the metal is approximately 69.3 g/mol.
An unknown metal chloride with the formula MCl3 undergoes electrolysis using a current of 6.50A for 1000 s and desposits 1.56g. What is the molar mass of the metal?
1 answer