Electrolysis Calculator

What is Electrolysis?

Electrolysis is a process that uses direct electric current (DC) to drive an otherwise non-spontaneous chemical reaction. It is a cornerstone of electrochemistry and is used in a wide range of industrial applications, including electroplating, refining metals, and producing chemicals like chlorine and sodium hydroxide.

Faraday's Laws of Electrolysis

The quantitative aspects of electrolysis are governed by Faraday's laws, which were formulated by Michael Faraday in the 19th century. Our calculator is based on these principles.

• Faraday's First Law: The mass of a substance altered at an electrode during electrolysis is directly proportional to the quantity of electricity transferred at that electrode.
• Faraday's Second Law: For a given quantity of electricity, the mass of an elemental material altered at an electrode is directly proportional to the element's equivalent weight.

The Formula Used in the Calculator

Combining Faraday's laws, we can derive a single formula to calculate the mass of a substance deposited or liberated during electrolysis:

mass = (I × t × MM) / (n × F)

• mass: The mass of the substance deposited, in grams (g).
• I: The total electric current, in amperes (A).
• t: The total time the current is applied, in seconds (s).
• MM: The molar mass of the substance, in grams per mole (g/mol).
• n: The number of moles of electrons transferred per mole of the substance in the half-reaction (e.g., for Cu²⁺ + 2e⁻ → Cu, n=2).
• F: Faraday's constant, approximately 96,485 coulombs per mole of electrons (C/mol e⁻).

How to Use the Electrolysis Calculator

1. Current (I): Enter the constant current that will be passed through the electrolytic cell in amperes.
2. Time (t): Enter the duration of the electrolysis in minutes. The calculator will convert this to seconds.
3. Molar Mass (MM): Input the molar mass of the substance being deposited or produced. For example, the molar mass of copper (Cu) is approximately 63.55 g/mol.
4. Moles of Electrons (n): Determine the number of electrons transferred in the balanced half-reaction for your substance. For example, reducing Ag⁺ requires 1 electron (n=1), while reducing Zn²⁺ requires 2 electrons (n=2).
5. Calculate: Click the "Calculate Mass Deposited" button to see the result.

Practical Example: Electroplating Copper

Imagine you want to electroplate an object with copper from a copper(II) sulfate solution (CuSO₄). You run a current of 1.5 A for 30 minutes. How much copper is deposited?

• I = 1.5 A
• t = 30 minutes
• MM of Cu = 63.55 g/mol
• The half-reaction is Cu²⁺ + 2e⁻ → Cu, so n = 2.

Using the calculator with these values, you would find that approximately 0.89 grams of copper are deposited onto the object.

Frequently Asked Questions (FAQ)

What is Faraday's constant (F)?

Faraday's constant represents the magnitude of electric charge per mole of electrons. It is the product of the elementary charge (e) and the Avogadro constant (Nₐ).

Does this calculator work for gases produced?

While this calculator solves for mass, you can use the result to find the volume of a gas. After calculating the mass, convert it to moles using the molar mass. Then, you can use the Ideal Gas Law (PV=nRT) to find the volume of the gas produced under specific temperature and pressure conditions.