Understanding Electrolysis: How Do Ions and Current Flow?

[Deep_Thinker97]

Right, I've started physics a level and electrolysis has always confused me since gcse, so please be very detailed!
This is what I know, (or assume) so far: there is a cell; that cell is connected to two electrodes; one is positive, the other is negative. The electrodes are placed in an ionic solution, where positive ions move to the negative electrode and negative ions move to the positive electrode.
I don't understand how current moves throughout the process. How do the electrodes get their charges in the first place? And overall, what direction does the current flow if the ions in the solution move in both directions!
Please help me!

 

[mikeph]

You attach the electrodes to a battery which makes one negative and one positive. An electric field will be produced between the two electrodes, and charges in an electric field experience an electric force. The positive and negative ions experience forces in the opposite direction.

The current takes the sign of the charge as well as its direction into account. A positive charge moving right to left gives the same current as a negative charge moving left to right. When the positive and negative ions move in opposite directions, they both add constructively to the total current.

1 amp of negative charge moving one direction + 1 amp of positive charge going the opposite direction = 2 amps total.

Whichever way you define this total current is a matter of convention, and I've forgotten which way humans conventionally decided on.

 

[adjacent]

A battery is connected to two electrodes put into a solution.The positive electrode is in the side of positive terminal of battery and vise versa.(Because the electrons in the Anode(Positive electrode) moves towards the positive terminal of battery making the electrode positively charges and vise versa).The cations move toward the cathode(negative electrode) and gets discharged,so,gaining electrons.The Anions(negative ions)moves toward the anode(positive electrode)giving electrons to the positive electrode which travels to the positive terminal,thus electrons flow through the circuit.

 

[Deep_Thinker97]

Thank you, i understand the process more now

 

[sardar]

Electrolysis is a process that uses electricity to break down a compound into its individual elements. It involves the use of an electric current to drive a non-spontaneous chemical reaction. This process is commonly used in industrial and laboratory settings to produce pure elements or compounds.

To understand how electrolysis works, it is important to first understand the concept of ions. Ions are atoms or molecules that have a positive or negative charge due to the loss or gain of electrons. In an ionic solution, such as a saltwater solution, there are positively charged ions (called cations) and negatively charged ions (called anions).

The setup for electrolysis involves a cell, which is a device that contains two electrodes and an electrolyte solution. The electrodes are usually made of inert materials, such as graphite or platinum, and are connected to a power source. One electrode is connected to the positive terminal of the power source and is called the anode, while the other electrode is connected to the negative terminal and is called the cathode.

When an electric current is passed through the cell, the positive ions in the solution are attracted to the negative electrode (cathode) and the negative ions are attracted to the positive electrode (anode). This movement of ions is called migration. At the electrodes, the ions gain or lose electrons, depending on their charge, and become neutral atoms or molecules. This process is called reduction (at the cathode) and oxidation (at the anode).

Let's take the example of electrolysis of water. Water (H2O) is a compound that contains two hydrogen ions (H+) and one oxygen ion (O2-). When an electric current is passed through the water, the hydrogen ions are attracted to the negative electrode (cathode) and gain electrons, forming hydrogen gas (H2). At the same time, the oxygen ions are attracted to the positive electrode (anode) and lose electrons, forming oxygen gas (O2). This process can be represented by the following chemical equation:

2H2O(l) → 2H2(g) + O2(g)

Now, let's address your questions about the flow of current and the charges on the electrodes. The flow of current in electrolysis is from the negative terminal of the power source to the positive terminal. This means that the electrons flow from the anode to the cathode through the external circuit. At the anode, electrons are being removed from