Electrolysis Calculator

Calculate mass deposited or gas produced in electrolysis using Faraday's laws. Find grams of product from current, time, and number of electrons per mole of product.

⚡ Electrochemistry📐 m = (I·t·M) / (n·F)🧪 Chemistry
Current I (A)
Time t (s)
Molar mass of product M (g/mol)
Electrons per ion n
Please enter valid values.

Formula & Reference

VariableSymbolFormulaUnits
Electrolysis CalculatorSee formulam = (I·t·M) / (n·F)g

Step-by-Step Examples

Example 1
Copper Plating

Plate copper (n=2, M=63.55) with 2.00 A for 1 hour (3600 s).

  • Q = I*t = 2.00 x 3600 = 7200 C
  • mol Cu = 7200/(2 x 96485) = 0.03731 mol
  • mass = 0.03731 x 63.55 = 2.370 g
✓ 2.370 g copper deposited
Example 2
Silver Plating

Plate Ag (n=1, M=107.87) with 0.500 A for 30 min (1800 s).

  • mol Ag = (0.500 x 1800)/(1 x 96485) = 0.009327 mol
  • mass = 0.009327 x 107.87 = 1.006 g
✓ 1.006 g silver plated
Example 3
Hydrogen Evolution

H2O electrolysis: produce H2 (n=2, M=2.016) with 5.00 A for 10 min (600 s).

  • mol H2 = (5.00 x 600)/(2 x 96485) = 0.01554 mol
  • mass H2 = 0.01554 x 2.016 = 0.0313 g
  • Volume at STP = 0.01554 x 22.4 = 0.348 L
✓ 0.0313 g (0.348 L at STP) of H2 produced

Real-World Applications

🏭
Electroplating Industry
Billions of parts plated annually: automotive, electronics, jewelry. Mass calculation via electrolysis.
⚗️
Metal Refining
Copper electrolytic refining uses Faraday laws. 99.99% pure Cu from anode dissolution and cathode deposition.
💧
Water Splitting
Green hydrogen production: water electrolysis. Mass of H2 per kWh calculated using Faraday laws.
🔋
Battery Charging
Charging is reverse electrolysis. Faraday laws determine charge state and material conversion.

Common Mistakes to Avoid

⚠️
n is electrons per formula unit, not charge

For Cu^2+: n=2. For Al^3+: n=3. For Ag+: n=1. For Cl2: n=2 (2Cl^- to Cl2 requires 2 electrons).

⚠️
Time must be in seconds

I (amperes) x t (seconds) = Q (coulombs). Convert minutes or hours to seconds.

⚠️
Faraday constant F = 96485 C/mol

F = charge of one mole of electrons = 96,485 C/mol electrons.

Frequently Asked Questions

What are Faraday's laws of electrolysis?
First law: mass deposited proportional to charge passed. Second law: for same charge, mass ratio = molar mass ratio / electron ratio.
What is a Faraday of charge?
1 Faraday = 96,485 C = charge of 1 mole of electrons. Passing 1 Faraday deposits 1 mol/n of a Mn+ ion.
How much current does industrial electrolysis use?
Aluminum smelting: 150,000 A at 4-5 V per cell. Each cell produces ~1 ton Al per day. Energy intensive: 13-14 kWh/kg Al.
What is current efficiency?
Actual mass / theoretical mass x 100%. Less than 100% due to side reactions (H2 evolution) and resistive losses.
How does electrolysis relate to fuel cells?
Reverse: fuel cell generates electricity from H2+O2. Electrolysis splits H2O using electricity. Same Faraday laws apply.

Related Chemistry Calculators

Formula Explorer connections

Interpretation: This formula links electron transfer, charge, potential, current or ionic transport in an electrochemical system. Assumption: Balance electron count and half-reactions, preserve sign conventions, and use consistent concentration, temperature and electrical units. Real cells include losses and overpotential.

Electrolysis Energy Calculator →Electroplating Mass Calculator →Faraday Electrolysis Calculator →Chemistry Formula Explorer →