Faraday's Law of Electrolysis Calculator

Calculate mass deposited or liberated during electrolysis using Faraday's laws. Essential for electrochemistry, electroplating, and battery design. Input current, time, and substance properties.

Current (I)

Time (t)

Molar Mass (M)

g/mol

Valence (z)

Results

Mass deposited: 1.184 g

Charge passed: 3600 C

Moles deposited: 0.01864 mol

Formula

m = (M × I × t) / (z × F)

Where F = 96485 C/mol (Faraday constant)

Common Elements Reference

Select an element to auto-fill molar mass and valence:

Understanding Faraday's Law

Faraday's laws quantify electrochemical deposition and dissolution. Essential for:

Electroplating thickness calculations
Battery capacity and efficiency analysis
Corrosion rate measurements
Industrial electrolysis process control

Calculation Steps

Convert all units to SI units (Amperes, Seconds, grams/mol)
Calculate total charge: Q = I × t
Compute moles of substance: n = Q / (z × F)
Calculate mass: m = n × M

Examples

Copper electroplating: 2A for 30 minutes (1800s) with Cu²⁺ (z=2, M=63.5 g/mol)

Q = 2 × 1800 = 3600 C
n = 3600 / (2 × 96485) ≈ 0.01864 mol
m = 0.01864 × 63.5 ≈ 1.184 g

Frequently Asked Questions

Why use 96485 C/mol for F?

This is the accepted value for the Faraday constant, representing the charge of one mole of electrons (approximately 96,485 coulombs).

Can I use this for molten salts?

Yes, but ensure correct valence values as oxidation states may differ from aqueous solutions.

How accurate is this calculation?

Theoretical values assume 100% current efficiency. Real-world applications may have 90-98% efficiency due to side reactions.

Formulas & Assumptions

First law: m ∝ Q
Second law: m ∝ M/z
Combined: m = (M × I × t)/(z × F)

Where:
m = mass deposited (grams)
M = molar mass (g/mol)
I = current (amperes)
t = time (seconds)
z = valence electrons
F = Faraday constant (96485 C/mol)

Constants:
Faraday constant F = 96485 C/mol (exact value per IUPAC)

Rounding: Results shown with 3 decimal places. Intermediate calculations use full precision.

Disclaimer: For educational and informational purposes only. Not for industrial process control or critical applications. Always verify against experimental data and consult professional standards for engineering applications.

Sources & References

IUPAC Gold Book - Faraday constant
ISO 80000-9: Quantities and units — Physical chemistry and molecular physics
ASTM B374 - Standard Terminology Relating to Electroplating

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Faradays Law Of Electrolysis Calculator

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