The oxidation reaction of alcohol and oxygen under the action of copper is detailed

In the first year of high school, there was an experiment in which copper wire was heated and ethanol was quickly inserted.

In the phenomenon, it can be observed that copper turns from black to red, so whether copper or copper oxide acts as a catalyst.

Why does black copper oxide turn red?

A: CU is for Catalyst Analysis: Ethanol Catalyzed Oxidation Reaction.

The process is as follows: 1) C2H5OH---CH3CHO+H2 (Condition: Heating) This is a reversible reaction that proceeds to a very small extent.

2) 2Cu + O2 = 2Cuo (Condition: Heating).

Cuo + H2 = Cu + H2O (Condition: Heating, Phenomenon: Black Cuo turns red) The above reaction is irreversible.

Add all the above equations to get the total reaction of ethanol-catalyzed oxidation:

2C2H5OH+O2---2CH3CHO+2H2O (conditions: Cu catalysis, heating).

Since Cu consumes H2, the total reaction is irreversible (when one step in a continuous reaction is irreversible, the total reaction is irreversible). Therefore, ethanol-catalyzed oxidation is an irreversible reaction that proceeds to a great extent.

The (—OH) hydroxyl group in the alcohol molecule loses one hydrogen, and the oxygen combines with carbon to form the (—cho) aldehyde group, and the lost hydrogen combines with oxygen to form water, which is the essence of this catalytic oxidation reaction.

1.Primary alcohols are oxidized to form aldehydes.

2.Secondary alcohols are oxidized to form ketones.

3.Tertiary alcohols are not easily oxidized.

There are two conditions for alcohol-catalyzed oxidation:

1. Transition metals such as Cu or Ag are used as catalysts and heated;

2. The carbon atom attached to the hydroxyl group is the hydrogen atom on the carbon atom.

Alcohol oxidation products are determined by the type of carbon atom to which the hydroxyl group is attached.

Alcohols, a large group of organic compounds, are compounds formed by the substitution of hydrogen atoms in the side chains of aliphatic, alicyclic or aromatic hydrocarbons by hydroxyl groups.

Alcohols are affected by hydroxyl groups and have intermolecular hydrogen bonds, and in water there are also hydrogen bonds between alcohol molecules and water molecules. Therefore, their physical properties are quite different from the corresponding hydrocarbons. It is mainly manifested in the relatively high melting and boiling point, and has a certain solubility in water.

1. The essence of alcohol catalytic oxidation is: dehydrogenation, that is, the combination of the hydroxyl group of alcohol and the hydrogen of the C atom connected to the hydroxyl group of the alcohol with the O atom of oxygen to remove h to form water.

2. Therefore, if there are 2 or 3 H atoms attached to the C atom with an alcohol hydroxyl group, then this alcohol catalyzes oxidation to form aldehydes.

3. The C atom bonded to the alcohol hydroxyl group has an H.

4. The product of alcohol catalytic oxidation is that the C atom of ketone linked to the alcohol hydroxyl group has no H atom, and this alcohol cannot be catalyzed, for example, CH3CH2OH ==CH3CH3(CH3) 2CHOH ==CH3COCH3(CH3)3C OH alcohol will not undergo catalytic oxidation.

Copper reacts with oxygen, and the copper surface turns from purplish-red to black, as follows:

Copper and oxygen reaction conditions are both possible for heating and high temperature, but the reaction products obtained are different under different conditions. They are: 2Cu+O = δ2CuO; 4cu + o = high temperature = 2cu o.

Copper is a transition element, the chemical symbol Cu, English copper, atomic number 29.

Pure copper is a soft metal, the surface is reddish-orange with metallic luster when it is first cut, and the elemental color is purple-red. Good ductility, high thermal and electrical conductivity, so it is the most commonly used material in cables and electrical and electronic components, and can also be used as a building material, which can form many alloys.

Copper alloys have excellent mechanical properties and very low resistivity, the most important of which are bronze and brass. In addition, copper is also a durable metal that can be used many times without compromising its mechanical properties.

Chemical equations

A chemical equation, also known as a chemical reaction equation, is a formula that uses a chemical formula to express the chemical reaction of a substance. Chemical equations reflect objective facts. Therefore, there are two principles to be observed in writing chemical equations:

First, it must be based on objective facts; The second is to abide by the law of conservation of mass.

The chemical equation not only indicates the reactants, products, and reaction conditions. At the same time, the stoichiometric number represents the quantitative relationship between the reactants and the product substances, and the mass relationship between the substances can also be expressed through the relative molecular mass or relative atomic mass, that is, the mass ratio between the substances. For gas reactants and products, the volume ratio can also be obtained directly from the stoichiometric number.

Oxidation of alcohols.

It refers to the carbon atom where the alcohol hydroxyl group is located under the action of Cu or Ag as a catalyst.

There must be hydrogen atoms on it.

During the reaction, the hydrogen atom on the alcohol hydroxyl group and any hydrogen atom on the carbon atom where the alcohol hydroxyl group is located break the bond, and the oxygen atom becomes double-built; If there is only one hydrogen on the carbon atom where the alcohol hydroxyl group is located, then the hydrogen and the hydrogen atom of the alcohol hydroxyl group break the bond and form a ketone.

If there is no hydrogen on the carbon atom where the hydroxyl group of the alcohol is located, then the reaction cannot take place; The reaction products are divided according to the type of alcohol participating in the reaction

1. Primary alcohols are oxidized to form aldehydes.

2. Secondary alcohol oxidizes to form ketones.

3. Tertiary alcohol is not easy to be oxidized.

The reaction phenomena of copper with oxygen are as follows:

Copper and oxygen react under heating or ignition conditions to form a black solid copper oxide. The chemical properties of copper are very stable, and the reaction phenomenon is not obvious in air. The reaction phenomenon of ignition in pure oxygen is that a large amount of heat is released, the flame is green, and the red surface gradually turns black.

The chemical formula of oxygen is O, relative molecular mass, colorless and odorless gas, and the most common elemental form of oxygen. Melting point, boiling point -183 . Not easily soluble in water, about 30ml of oxygen is dissolved in 1L of water. In the air, oxygen accounts for about 21%.

Liquid oxygen is a sky-blue liquid, and solid oxygen is a blue crystal. It is not very active at room temperature, and it is not easy to interact with many substances. However, it is very active at high temperatures and can be directly combined with a variety of elements, which is second only to fluorine in electronegativity with oxygen atoms.

Oxygen is the most widely distributed in nature, and it is the most abundant element in the crustal mass. Oxygen is needed for hydrocarbon oxidation, wastewater treatment, rocket propellants, and respiration for animals and humans in aviation, spaceflight, and diving. Animal respiration, combustion, and all oxidation processes, including organic matter, consume oxygen.

Oxygen is chemically more reactive. With the exception of rare gases and less reactive metal elements such as gold, platinum, and silver, most of the elements can react with oxygen, and these reactions are called oxidation reactions, and the compounds produced by the reactions (composed of two elements, one of which is oxygen) are called oxides.

Do you want to ask about the reaction steps of cyclohexanol and copper hydroxide? The reaction steps are as follows:

1. Prepare reactants: weigh an appropriate amount of bright cyclohexanol and copper hydroxide. Note that copper hydroxide usually exists in solid form and needs to be dissolved in an appropriate solvent, such as water or ethanol.

2. Reaction mixing: Mix cyclohexanol and hydroxide bond-de-bonding copper solution together. Stir the mixture to ensure that the reaction proceeds evenly.

3. Reaction progression: At room temperature, observe the change of the mixture. As the reaction progresses, the color of the mixture may change, gradually changing from blue-green to pale yellow.

4. End of reaction: When the reaction reaches a certain level, the reaction can be stopped. At this point, cyclohexanol has been oxidized to pin and cyclohexanone.