Electrolysis Calculator
Free Electrolysis Calculator for electrochemistry. Enter variables to compute results with formulas and detailed steps.
Formula
m = (I * t * M) / (n * F)
The mass deposited (m) equals current (I) times time (t) times molar mass (M), divided by the number of electrons per ion (n) times Faraday's constant (F = 96,485 C/mol). This is the quantitative form of Faraday's first law of electrolysis.
Worked Examples
Example 1: Copper Electroplating
Problem: How much copper is deposited by passing 3 amperes for 2 hours through CuSO4 solution? Cu2+ requires 2 electrons, M = 63.55 g/mol.
Solution: Q = I * t = 3 * 7200 = 21,600 C\nMoles of electrons = 21600 / 96485 = 0.2239 mol\nMoles of Cu = 0.2239 / 2 = 0.1119 mol\nMass = 0.1119 * 63.55 = 7.114 g
Result: Mass deposited = 7.114 g of copper
Example 2: Aluminum Production
Problem: Calculate the mass of aluminum produced by 100 A for 24 hours. Al3+ requires 3 electrons, M = 26.98 g/mol.
Solution: Q = 100 * 86400 = 8,640,000 C\nMoles of electrons = 8640000 / 96485 = 89.55 mol\nMoles of Al = 89.55 / 3 = 29.85 mol\nMass = 29.85 * 26.98 = 805.5 g
Result: Mass produced = 805.5 g (0.806 kg) of aluminum
Frequently Asked Questions
What is electrolysis?
Electrolysis is a chemical process that uses electrical energy to drive a non-spontaneous chemical reaction. It involves passing a direct current through an electrolyte (a solution or molten compound containing ions) using two electrodes. At the cathode (negative electrode), cations gain electrons (reduction), and at the anode (positive electrode), anions lose electrons (oxidation). Common applications include electroplating metals, refining copper, producing aluminum from bauxite, generating hydrogen and oxygen from water, and manufacturing chemicals like chlorine and sodium hydroxide. The process is governed by Faraday's laws of electrolysis.
What are Faraday's laws of electrolysis?
Faraday's first law states that the mass of substance deposited or dissolved at an electrode is directly proportional to the total electric charge passed through the electrolyte. Mathematically, m = (Q * M) / (n * F), where m is mass, Q is charge (current times time), M is molar mass, n is the number of electrons transferred per ion, and F is Faraday's constant (96,485 C/mol). Faraday's second law states that when the same quantity of charge passes through different electrolytes, the masses of substances deposited are proportional to their equivalent weights (molar mass divided by the charge number). These laws are fundamental to quantitative electrochemistry.
What factors affect electrolysis efficiency?
Several factors influence electrolysis efficiency. Current efficiency refers to the fraction of total charge that produces the desired product; side reactions like hydrogen evolution or oxygen evolution can reduce this below 100 percent. Overpotential is the extra voltage needed beyond the thermodynamic minimum to drive the reaction at a practical rate, and it varies with electrode material, surface area, and current density. Temperature affects both ion mobility and reaction kinetics, with higher temperatures generally improving efficiency. Electrode material and geometry influence the overpotential and current distribution. Solution concentration and agitation ensure adequate ion supply to the electrodes and prevent concentration polarization.
How do I get the most accurate result?
Enter values as precisely as possible using the correct units for each field. Check that you have selected the right unit (e.g. kilograms vs pounds, meters vs feet) before calculating. Rounding inputs early can reduce output precision.
Can I use the results for professional or academic purposes?
You may use the results for reference and educational purposes. For professional reports, academic papers, or critical decisions, we recommend verifying outputs against peer-reviewed sources or consulting a qualified expert in the relevant field.
How accurate are the results from Electrolysis Calculator?
All calculations use established mathematical formulas and are performed with high-precision arithmetic. Results are accurate to the precision shown. For critical decisions in finance, medicine, or engineering, always verify results with a qualified professional.