Electrolysis (Faraday Law) Calculator

Work out electrolysis (faraday law) instantly with clear inputs, formula shown and shareable results.

About Electrolysis (Faraday Law) Calculator

Faraday's law ties deposited mass to charge: one mole of electrons is 96,485 C, and each ion needs n of them. So mass = ItM/(nF). Two amps for an hour is 7200 C, which plates 2.37 g of copper from Cu2+ because the divalent ion consumes two electrons per atom.

Formulas

Faraday's law

mass = (I x t x M) / (n x F)

Charge passed

Q = I x t

Worked example

With the default values below, Electrolysis (Faraday Law) Calculator returns Mass Deposited of 2.3711. Change any input above and every figure here is recalculated in your browser.

Inputs used

Currentminimum 0 A: 2 A
Durationminimum 0 s: 3,600 s
Molar mass of the deposited elementminimum 0 g/mol: 63.55 g/mol
Electrons per ion (n)minimum 1: 2

Results

Mass Deposited: 2.3711 g
Charge Passed: 7,200.0 C
Moles Deposited: 3.7311 × 10⁻²
Moles Of Electrons Passed: 7.4623 × 10⁻²

Step by step

1Values used
2Faraday's law
3Charge passed
4Mass Deposited= 2.3711 g
5Charge Passed= 7,200.0 C
6Moles Deposited= 0.0373
7Moles Of Electrons Passed= 0.0746

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 4 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

What if the cell is less than 100% efficient?

Multiply the mass by the current efficiency. Side reactions such as hydrogen evolution consume charge without depositing metal.

Why does the ion charge matter so much?

Aluminium at n = 3 needs half again as much charge per mole as a divalent metal, which is why aluminium smelting is so energy hungry.