Elektrolisis bagian 2 -HUKUM FARADAY 1

Summary

This educational video explores the quantitative relationship between the amount of substance reacting and the electric charge involved in electrochemistry, focusing on Faraday's First Law. The law, named after English scientist Michael Faraday, establishes that the mass of a substance deposited at an electrode is proportional to the electric charge passed through the cell. The video uses the formula m = e * I * t / (n * F) to calculate the mass of metals produced at the cathode during electrolysis, where m is mass, e is the equivalent mass, I is current, t is time, n is the number of electrons transferred, and F is Faraday's constant. Practical examples, including the electrolysis of CuSO4 and AgNO3 solutions, demonstrate how to apply this law to determine the mass of metals produced.

Takeaways

• 🔬 The video discusses the quantitative relationship between the amount of substance reacting and the electric charge involved, known as Faraday's laws of electrolysis.
• 🌐 Faraday's laws are named after the English scientist Michael Faraday, a physicist and chemist who formulated these principles.
• ⚡ The first law of Faraday states that the mass of a substance deposited at an electrode is directly proportional to the quantity of electric charge passed through the solution.
• 🔋 The formula m = e * I * t / (n * F) is used to calculate the mass of the substance produced, where m is mass, e is the equivalent mass of the substance, I is current, t is time, n is the number of electrons transferred, and F is Faraday's constant.
• 🔢 Faraday's constant (F) is approximately 96,500 C/mol, representing the charge of one mole of electrons.
• 🏗️ The video provides examples of how to calculate the mass of metals deposited at the cathode during electrolysis, using the formula and Faraday's constant.
• ⚖️ The script includes a problem-solving session where the audience is guided through calculating the mass of copper, silver, and magnesium produced during electrolysis.
• 🕒 Time is a crucial factor in these calculations, and it must be converted into seconds when used in the formula.
• 🔋 The valency of the metal ion in the electrolyte solution is essential for determining the mass of the metal deposited, as it affects the number of electrons involved in the reaction.
• 🔌 The video also covers the calculation of the electric current required to produce a specific mass of a metal during electrolysis, demonstrating the application of Faraday's laws in practical scenarios.
• 📚 Understanding Faraday's laws is fundamental for solving problems related to electrolysis and is emphasized as a key learning outcome of the video.

Q & A

What is the relationship between the amount of substance reacting and the electric charge involved according to Faraday's laws?

Faraday's laws establish a quantitative relationship between the amount of substance reacting and the electric charge involved, allowing us to determine the quantity of a substance reacting based on the amount of electric charge passed through an electrolyte in a given time.

Why is the law named Faraday's law?

The law is named Faraday's law because it was formulated by the English scientist Michael Faraday, a physicist and chemist known for his work in electromagnetism and electrochemistry.

What is the formula used to calculate the mass of a substance produced at an electrode according to Faraday's first law?

The formula used to calculate the mass of a substance produced at an electrode is m = e * I / (n * F), where m is the mass, e is the equivalent mass of the substance, I is the current in amperes, n is the number of electrons involved in the redox reaction, and F is Faraday's constant.

What is the value of Faraday's constant and what does it represent?

Faraday's constant is approximately 96,500 coulombs per mole of electrons. It represents the amount of electric charge carried by one mole of electrons.

How can you calculate the mass of copper deposited at the cathode during electrolysis of a CuSO4 solution with a given current?

To calculate the mass of copper deposited, you would use the formula m = (M * I * t) / (n * F), where M is the molar mass of copper, I is the current in amperes, t is the time in seconds, n is the valency of copper, and F is Faraday's constant.

What is the molar mass of copper and how is it used in Faraday's law calculations?

The molar mass of copper is 63.5 g/mol. It is used in Faraday's law calculations to determine the mass of copper deposited at the cathode during electrolysis by multiplying it with the current, time, and valency, and then dividing by Faraday's constant.

How do you determine the mass of silver produced by passing a current through a AgNO3 solution?

The mass of silver produced can be determined using the formula m = (M * I * t) / (n * F), where M is the molar mass of silver, I is the current in amperes, t is the time in seconds, n is the valency of silver, and F is Faraday's constant.

What is the valency of silver in the context of the electrolysis of AgNO3?

In the context of the electrolysis of AgNO3, silver has a valency of one, as it forms Ag+ ions in the solution.

How can you calculate the current required to produce a specific mass of magnesium through the electrolysis of MgCl2?

The current required to produce a specific mass of magnesium can be calculated using the formula I = (m * n * F) / (M * t), where m is the mass of magnesium, n is the valency of magnesium, F is Faraday's constant, and t is the time in seconds.

What is the relative atomic mass of a metal produced at the cathode with a known current, time, and mass of the metal?

The relative atomic mass of the metal can be calculated using the formula M = (m * F) / (n * I * t), where m is the mass of the metal, F is Faraday's constant, n is the valency of the metal, I is the current in amperes, and t is the time in seconds.

How does the valency of a metal ion affect the amount of metal deposited during electrolysis?

The valency of a metal ion affects the amount of metal deposited during electrolysis because it determines the number of electrons required to reduce one mole of the metal ions to metal atoms, which in turn affects the amount of charge needed for the deposition process.