What are the characteristics of galvanic cells and electrolytic cells?

Electrolysis is the passing of an electric current through an electrolyte solution (or melted electrolyte).

The process of causing redox reactions at the cathode and anode.

Energy Conversion During Electrolysis Electrical energy is converted into chemical energy.

The conditions under which the electrolytic reaction occurs.

two electrodes connected to the power supply;

electrolyte solution (or melted electrolyte);

The two electrodes are immersed in an electrolyte solution, creating a closed loop.

The galvanic cell uses the difference in metallicity between the two electrodes to produce an electric potential difference, so that the flow of electrons can produce an electric current. Also known as non-storage battery, it is a kind of electrochemical battery, and its electrochemical reaction is reversed differently, that is, it can only convert chemical energy into electrical energy, simply put, it cannot re-store electricity, as opposed to the battery.

A device that converts chemical energy into electrical energy. Therefore, according to the definition, ordinary dry batteries and fuel cells can be called primary batteries. The basic conditions for the composition of galvanic cells are:

Two metals (or graphite) with different reactivity are connected with wires and inserted into the electrolyte solution. The generation of the current is due to the oxidation reaction and the reduction reaction being carried out on the two electrodes, respectively. In general, in galvanic batteries, the more reactive metal is the negative electrode, and the less active metal is the positive electrode.

The negative electrode itself is prone to oxidation reaction, and the electrons flow along the wire to the positive electrode, and the positive electrode is generally reduced by the cation electrons in the electrolyte solution. In galvanic cells, the outer circuit conducts electricity with electrons, and in the electrolyte solution, it conducts with ions.

Primary battery A device that directly converts the chemical energy in the active substance into electrical energy output through redox reaction. Also known as chemical batteries. Because the reversibility of the redox reaction of various types of galvanic batteries is very poor, they cannot be reused after discharge, so they are also called primary batteries.

It is typically composed of a positive electrode, a negative electrode, an electrolyte, a separator, and a housing, and can be made in a variety of shapes and sizes for ease of use. It is widely used in industry and agriculture, defense industry and communications, lighting, medical and other departments, and has become a power supply for commonly used electrical appliances such as radios, tape recorders, cameras, calculators, electronic watches, toys, and hearing aids in daily life. Primary batteries are generally divided into zinc-manganese batteries, zinc-air batteries, zinc-silver batteries, zinc-mercury batteries, magnesium-manganese batteries, lithium fluorocarbon batteries, lithium sulfur dioxide batteries, etc. according to the negative active materials (such as zinc, cadmium, magnesium, lithium, etc.) and the positive active materials (such as manganese, mercury, sulfur dioxide, etc.).

Zinc-manganese batteries have the largest output, which are often divided into ammonium chloride type and zinc chloride type according to the electrolyte, and are divided into paste batteries and low-pole batteries according to their isolation layers. Zinc-manganese batteries with potassium hydroxide as the electrolyte are customarily called alkaline zinc-manganese batteries because of the different structure of their negative electrodes (zinc) from other zinc-manganese batteries, which are called alkaline zinc-manganese batteries for short[1], commonly known as alkaline batteries.

A galvanic battery is a transducer that converts chemical energy directly into electrical energy. After continuous discharge or intermittent discharge, the active material of the two electrodes cannot be charged with reverse current to restore the active material of the two electrodes to the initial state, that is, the active material of the electrode can only be used once. Therefore, it is also called disposable battery.

Remember a few words:

Galvanic battery: loss of high oxygen negative (loss of electrons, valency increases, oxidized, is the negative electrode) low and positive (electrons are obtained, valency is reduced, is reduced, is positive) electrons from the negative electrode through the external circuit to.

Cathode electrolytic cell: oxygen yang to yin (loss of electrons, oxidation, anode; Electrons are obtained, reduced, and made as cathodes) Due to the action of the applied electric field, the cations in the electrolytic cell move directionally, and the anode moves to the cathode to generate current.

Galvanic batteries can generate electric current and are themselves a power source.

The electrolytic cell requires a power supply for electrolysis and is itself an electrical appliance.

1. The essential difference between the electrolytic cell and the galvanic cell: the electrolytic cell converts electrical energy into chemical energy. Galvanic batteries convert chemical energy into electrical energy.

2. The difference between the electrolytic cell and the galvanic battery device: the electrolytic cell has an external power supply. The primary battery has no external power supply.

3. The difference between the electrolytic cell and the electron flow direction of the galvanic cell: the electron flow direction of the galvanic cell is just opposite to the direction of the current (the current is positive and the electrons are negative). The electrolytic cell is just the opposite of the electron flow of the galvanic cell (electrons flow out of the electrode into the cell).

galvanic cells andElectrolytic cellThe knowledge points are as follows:

1. Cathodic protection of the external power supply.

Method: Connected to the outer tung absolute.

The DC power supply forms the electrolytic cell, and the protected metal is used as the cathode.

2. The solvent does not change, but it is actually the absolute quality of the electrolytic solution, and the pH increases.

3. Discharge and charging are completely opposite processes, discharge as galvanic battery, charging as electrolytic cell. The name of the electrode depends on the gain and loss of electrons, and the writing requirements of the electrode reaction formula and the ion equation.

and should add up to the same as the total reaction.

4. There is a wire connection between the two electrodes to form a closed loop.

5. The composition of the galvanic battery is expressed by diagram, which is too troublesome. In order to be easy to write, the device of the galvanic battery is often represented by convenient and scientific symbols.

Primary battery lead scrambling:A device that generates an electric current through a redox reaction is called a galvanic battery, and it can also be said to be a device that converts chemical energy into electrical energy. Some galvanic cells can constitute a reversible battery, while others are not.

When the galvanic battery is discharged, the negative electrode undergoes an oxidation reaction and the positive electrode undergoes a reduction reaction.

Electrolytic cellThe main application of the electrolytic cell is for the industrial production of high-purity metals, and is a device for converting electrical energy into chemical energy (composition: external power supply, electrolyte solution, cathode and cation electrodes).

The process of passing an electric current through an electrolyte solution or molten electrolyte to cause a reduction oxidation reaction at the cathode and anode.

Writing about the electrode reaction formula:

In the study of electrochemistry, it is necessary to grasp the different essences (spontaneous and non-spontaneous) of galvanic cells and electrolytic cells.

1.For galvanic batteries, the writing method of the reactive formula and the total reactive formula of the Qili electrode is generally:

Step 1: Determine the positive and negative electrodes; Step 2: Determine the electrode reaction according to the participation of ions in the negative electrode and the solution; Step 3:

Add the electrode reactions together to obtain the total reaction formula. The "addition method" of galvanic cells must be mastered, with this magic weapon, for any galvanic cell reaction, as long as you first write an easy-to-write one-pole reaction formula, and subtract the reaction formula of one of the poles with the total reaction formula, you can get the reaction formula of the other pole (pay attention to the conservation of charge).

2.For electrolytic cells, the electrode reaction and total reaction formulas are generally written as follows: Step 1:

The material and cathode of the electrode are quietly excited; Step 2: Analyze and judge the electrode reaction according to the electrode material and solution medium; Step 3: Add the electrode reactions to obtain the total reaction formula (note the situation when water is electrolyzed).