Aldehydes and ketones are in the group of carbonyl compounds, and represent a hydrocarbon molecule.Simply put, aldehydes - a compound of carbon and hydrogen atoms, and ketones - carbonyl compound with carbon residues aldehydes.Typically, a combination of a carbonyl group and an aldehyde group is called hydrogen, and themselves aldehydes and ketones - oxidizing compound.
Except formaldehyde, which has a gaseous form, and all other kinds of aldehydes and ketones are mobile liquid having a boiling point which is much lower than the temperature of the carbon with the same number of atoms.Hydrogen, which is part of the aldehydes, allowing them to completely dissolve in water.
Getting aldehydes occurs in different ways, different in complexity and substance with which the oxidation of the hydrocarbon.The simplest type of aldehyde called formaldehyde obtained when oxygen and methane with small amounts of copper-zinc material.Preparation of aldehyde and ketone compound depends on various chemicals, and the number of atoms involved in the oxidation.
acids which are obtained after the aldehyde compounds and other substances having the same carbon substrate.The names of the aldehyde products are most commonly used Russian trivial names that match the name of the final acid, which is converted into an aldehyde.For example, several names of aldehydes: formic, acetic, propionic, butyric and isobutyraldehyde.Each of them is different from each other in the number of atoms.Preparation of aldehydes is mainly due to the oxidation of primary alcohols.It is the most important of all known methods of obtaining the substance.
Acetaldehyde is obtained by the combination of alcohol and potassium dichromate, and is held, this procedure almost always in the laboratory.The second way in which is received aldehydes atoms in the compound is an alcohol, oxygen and a metal.Most often it is platinum as this metal is the most active action.You can also use copper powder, but to work with him more difficult.For its compounds must be heated to a high temperature copper.
reaction in which oxygen is involved, can be repeated any number of times.The oxidation of copper with oxygen obtained methyl alcohol.A Receive benzoic aldehyde, halogen atoms, by a chemical reaction on the hydroxyl group.
Each individual aldehyde has its chemical properties, which, in turn, react with other substances.These reactions can be divided into several groups, with the groups of atoms.First, the compound is silver oxide.When connecting silver oxide and an aldehyde, and heating the mixture in the tube, you can see a metal plaque.If added to an aldehyde of copper oxide and heated at a high temperature, a blue precipitate of copper hydroxide turns into yellow.That is, the substance is converted to the acid.It should also be noted that if the yellow mixture was heated, at the end it turns red.
Preparation of aldehydes with aromatic properties, and oxidation proceeds for a long time and, eventually, leads to the appearance of the perbenzoic acid.
Among other things, you can pay attention to the reaction of an aldehyde called Cannizzaro reaction.During this reaction, one of the two molecules of the aldehyde is converted to the acid, and the second - back to the alcohol.All of the above methods for the preparation of aldehydes more confusing and perhaps incomprehensible to the ignorant man, however, important to remember that virtually all aldehydes are very toxic and can accumulate in the human body.
