Is the experiment of electrolysis of water a physical change, or a chemical reaction? Why

Chemical reaction. The so-called physical change refers to the change in the physical state of matter (that is, the mutual transformation of gaseous, solid, and liquid states), and the essence of matter has not changed, that is to say, the chemical properties have not changed, such as ice, water, water vapor, no matter what it is, we all know that it is water, and it cannot be burned.

The smallest unit of a chemical reaction is an atom, that is, after a chemical change in a substance, the product becomes another substance, such as the electrolysis of water into hydrogen and oxygen, water cannot be burned, but hydrogen can.

As long as there is a break of a chemical bond during the reaction, it is a chemical change.

Electrolysis of water h-o-h The molecular structure of the substance is destroyed and the properties of the substance are destroyed to form h-h (hydrogen) o=o (oxygen) and hence the chemical change.

Whereas, physical changes do not change the properties of matter, such as nuclear reactions Nuclear reactions are only changes in atoms, but there is no change in chemical bonds.

Chemical changes as new substances are formed.

2H2O=== Electrolysis ===2H2 (gas) + O2 (gas).

Both. First, it starts with a chemical reaction to produce hydrogen and oxygen.

At the same time, the physical quantity of water, that is, the amount of water, is gradually decreasing, and the reduced part is already producing hydrogen and oxygen.

Matter is not extinguished, hydrogen and oxygen are not reduced, but water - it is reduced.

- Intuitively, the amount of water has decreased, and who can see hydrogen and oxygen?

That's what we do.

Chemical changes, new substances are formed.

When a new substance is generated, it is a chemical change.

The chemical reaction generates new substances H2 and O2

Chemical reactions generate new substances.

The water electrolysis experiment is an experiment that tests the composition of water. The experimental phenomenon is that there are bubbles in the test tube, and the gas ratio produced by the test tube connected to the positive electrode (oxygen) and negative electrode (hydrogen) of the power supply is 1:2 (memorize the formula: hydrogen dioxide one, yang oxygen and yin hydrogen).

According to the product produced during electrolysis, electrolysis can be divided into several types, such as water electrolysis, decomposition electrolyte type, hydrogen release alkali type, oxygen release acid type, etc. Water is made up of two elements, hydrogen and oxygen. Water is electrified to produce hydrogen and oxygen.

The positive electrode produces oxygen, and the negative electrode produces hydrogen. Before and after the chemical reaction, the element species remains the same. In chemical change, molecules can be divided into atoms, and atoms are indivisible and can form new molecules.

Water is made up of two elements, hydrogen and oxygen. The chemical reactions that occur in the above experiments are decomposition reactions. There are eight words that can be simply summed up:

Positive oxygen and negative hydrogen. Hydrogen dioxyone. In water (molecule), the ratio of the number of atoms of hydrogen and oxygen is 2:

1. The ratio of the number of molecules is 2:1, the volume ratio is 2:1, and the mass ratio is 1:

8。Pure water is non-conductive, and a small amount of sodium sulfate or sodium hydroxide or dilute sulfuric acid can be added to the water to enhance the conductivity.

At the beginning of the experiment, the volume ratio of oxygen to hydrogen did not match 1:2 because oxygen was not easily soluble in water, but it would dissolve a small part; Hydrogen is insoluble and has a slower reaction rate, so there is less hydrogen.

3.Be sure to drain the air from the electrolyzer and close the pistons.

According to the "positive oxygen and negative hydrogen, hydrogen dioxide one", it can be seen that in the electrolysis reaction, the gas collected by the positive electrode is oxygen; The gas collected by the negative electrode is hydrogen, and the volume ratio of oxygen and hydrogen gas is about 1:2; This experiment proved that water is composed of hydrogen and oxygen, and the literal expression for the electrolysis of water reaction: water.

Energized hydrogen + oxygen

So the answer is: oxygen; Hydrogen; Combustible; 1：2；It is composed of hydrogen and oxygen; Water electrified hydrogen + oxygen

Electrolysis of water is a chemical change

1.What is electrolyzed water

Electrolysis is the process of placing two metal or carbon rods in a substance to be decomposed, and then connecting a power source to pass an electric current through the liquid. The cation of the compound moves to the negatively charged electrode, which is the cathode, and the anion moves to the positively charged electrode, which is the anode, so the compound is divided into two poles. The process of using electricity to decompose a compound is the electrolysis process.

Electrolyzed water is currently recognized as the safest and most advanced water in the world's advanced countries, and it is also water that meets the "Six Standards of Good Water" of the World Health Organization. So far, the electrolyzed water industry has been greatly developed in Europe, the United States, Japan, South Korea, Taiwan and Southeast Asia.

2.Characteristics and functions of acidic electrolyzed water

It meets the acidity requirements of the human epidermis, can remove the dirt in the pores with a halo effect, and plays a role in astringency and elasticity, which can be used for beauty care. Strong acidic electrolyzed water has a good antibacterial effect and can be used to clean the body and daily necessities. Acidic electrolyzed water can effectively deal with ** inflammation, and can also converge and cut wounds, and quickly stop bleeding and sterilize.

3.Characteristics and functions of alkaline electrolyzed water

Alkaline electrolyzed water is weakly alkaline, which can neutralize various acidic metabolites in the body, prevent the body from becoming acidic, and thus prevent the occurrence of various diseases. Alkaline electrolyzed water has strong penetration and solubility, which can effectively promote metabolism, carry out "sail preparation and internal cleaning" on the human body, quickly eliminate toxins in the body, and improve the body's immune function.

Alkaline electrolyzed water can eliminate excessive "free radicals" in the body and delay the aging of tissues and organs. Alkaline electrolyzed water contains electrolyte minerals such as cymbal, magnesium, zinc, etc., which are easy to dry up and absorbed by the human body, and can supplement the trace mineral elements that the human body lacks.

4.Chemical reaction.

The process by which molecules break down into atoms, and the atoms rearrange and combine to form new substances, is called a chemical reaction. In the reaction, it is often accompanied by luminescence, heat, discoloration, and the formation of precipitate, etc., and the basis for judging whether a reaction is a chemical reaction is whether the reaction generates new substances.

Electrolysis of water is a chemical changeWater electrolysis is when the water molecule first becomes an oxygen atom and a hydrogen atom, then two oxygen atoms become oxygen and two hydrogen atoms become hydrogen gas. So it's the creation of new substances.

The water molecule itself is made up of hydrogen atoms and oxygen atoms rather than molecules, so it produces new matter. So electrolysis of water is a chemical change.

Parenchyma. The essence of chemical change can be understood from a microscopic perspective: the type and number of atoms before and after a chemical reaction do not change, but only the way of bonding between atoms has changed, and atoms are the smallest particles of chemical change.

For example, in the case of a substance made up of molecules, it is a molecule in which atoms are recombined into a new substance.

The chemical properties of a substance can only be expressed through chemical changes in the substance, so the chemical properties of the substance can be studied by the method of making the substance react chemically and a new substance can be prepared.

Electrolysis of water produces hydrogen and oxygen, which is a chemical change. Electrolyzed water generally refers to the product produced by the electrolysis of water containing salts (such as sodium chloride). The electrolyzed water itself is neutral and other ions can be added, or it can be separated by a semi-permeable membrane to form water with both properties.

Electrolyzed water generally refers to the product produced by the electrolysis of water containing salts (such as sodium chloride). The electrolyzed water itself is neutral and other ions can be added, or it can be separated by a semi-permeable membrane to form water with both properties.

One of them is alkaline ionized water and the other is acidic ionized water. Electrolyzed water with sodium chloride as the electrolyte contained in water will contain sodium hydroxide, hypochlorous acid and sodium hypochlorite after electrolysis (if pure water is electrolyzed, only hydroxide ions, hydrogen gas, oxygen and hydrogen ions will be produced).

Chemical change refers to the process of conversion or transfer of atoms or electrons between molecules in contact with each other to form new molecules accompanied by changes in energy, which is essentially the breaking of old bonds and the formation of new bonds.

Chemical changes are always accompanied by physical changes. In the process of chemical change, there are usually luminescence, exothermia, and endothermy. According to the atomic collision theory, the chemical change between molecules is accomplished through collision, and two conditions need to be met to complete the collision of the molecule that reacts

1) Have sufficient energy; (2) Correct orientation. Because the reaction needs to overcome a certain molecular energy barrier, it must have a higher energy to overcome the molecular energy barrier. Two colliding molecules must have the correct orientation for the old bond to break.