Aldehydes and ketones are included in the group of carbonyl compounds, and are hydrocarbon molecules. Simply put, aldehydes are a combination of carbon and hydrogen atoms, and ketones are a combination of carbonyl carbon with aldehyde residues. As a rule, the combination of a carbonyl group and hydrogen is called an aldehyde group, and the aldehydes and ketones themselves are called oxidative compounds.
Apart from formaldehyde, which has a gaseous form, all other types of aldehydes and ketones are mobile liquids, the boiling point of which is much lower than the temperature of carbon with the same number of atoms. Hydrogen, which is part of aldehydes, allows them to completely dissolve in water.
Obtaining aldehydes occurs in various ways, differing in complexity and substance, with which the oxidation of hydrocarbon occurs. The simplest type of aldehyde, called formaldehyde, is obtained by combining oxygen and methane, with a small addition of copper-zinc substance. Obtaining aldehydes and ketones depends on the combination of various chemicals, and on the number of atoms involved in the oxidation.
Acids that are obtained after combining the aldehyde and another substance have the same carbon base. In the names of the obtained aldehydes, Russian trivial names are most often used, corresponding to the name of the final acids into which the aldehyde is converted. For example, here are a few names of aldehydes: formic, acetic, propionic, butyric and isobutyric aldehydes. And each of them differs from each other in the number of atoms. Obtaining aldehydes occurs mainly due to the oxidation of primary alcohols. This is the most important of all known methods for producing this substance.
Acetic aldehyde is obtained by combining alcohol and potassium dichromate, and this procedure is carried out almost always in the laboratory. The second way, due to which the production of aldehydes occurs, is to combine the atoms of alcohol, oxygen and metal. Most often it is platinum, since this metal has the most active effect. You can also use copper powder, although working with it is somewhat more difficult. To connect it, it is necessary to heat copper to high temperatures.
Reactions in which oxygen is involved can be repeated an unlimited number of times. When copper is oxidized with oxygen, methyl alcohol is obtained. And upon receipt of benzoic aldehyde, halogens from atoms, as a result of a chemical reaction, on hydroxyl.
Each individual aldehyde has its own chemical properties, which, in turn, react with other substances. These reactions can be divided into several groups, with the corresponding groups of atoms. The first is a compound with silver oxide. When silver oxide and aldehyde are combined and the mixture is heated, a metal coating can be seen in the test tube. If copper oxide is added to the aldehyde and heated at high temperature, the blue precipitate of copper hydroxide turns yellow. That is, the substance turns into acid. It is also worth noting that if you heat the yellow mixture, then in the end it will turn red.
Obtaining aldehydes with aromatic properties, and its oxidation occurs over a long time, and, in the end, leads to the appearance of superbenzoic acid.
Among other things, you can pay attention to the aldehyde reaction, called the Cannizzaro reaction. During this reaction, one of the two molecules of the aldehyde is converted to acid, and the second is converted back to alcohol. All of the above methods for producing aldehydes are somewhat confusing and perhaps incomprehensible to an ignorant person, however, it is important to remember that almost all aldehydes are very toxic, and can accumulate in the human body.