Qualitative reactions to organic matter,Ions and cations can determine the presence of various compounds using available, in most cases simple methods. They can be carried out using indicators, hydroxides, oxides. The science that studies the properties and structure of various substances is called "chemistry." Qualitative reactions are part of the practical section of this science.
Classification of inorganic substances
All substances are divided into organic andinorganic. The first group includes such classes of compounds as salts, hydroxides (bases, acids, and amphoteric) and oxides, and also simple compounds (СІ2, І2, Н2, and others, consisting of one element).
Salts consist of a cation of a metal, andalso the anion of the acid residue. Acid molecules include H + cations and acid residue anions. Hydroxides are composed of metal cations and anions in the form of the OH- hydroxyl group. The composition of oxide molecules includes atoms of two chemical elements, one of which is necessarily oxygen. They can be acidic, basic and amphoteric. As their name implies, they are able to form different classes of substances during certain reactions. For example, acidic oxides form acids when reacting with water, and basic ones form bases. Amphoteric, depending on the conditions, can exhibit the properties of both types of oxides. These include compounds of iron, beryllium, aluminum, tin, chromium, lead. Their hydroxides are also amphoteric. In order to determine the presence of various inorganic substances in the solution, qualitative reactions to ions are used.
Variety of organic matter
This group includes chemical compounds, the composition of which molecules necessarily include carbon and hydrogen. They may also contain atoms of oxygen, nitrogen, sulfur and many other elements.
They are divided into the following main classes:alkanes, alkenes, alkynes, organic acids (nucleic, fatty, saturated, amino acids, etc.), aldehydes, proteins, fats, carbohydrates. Many qualitative reactions to organic substances are carried out using a variety of hydroxides. Reagents such as potassium permanganate, acids, oxides can also be used for this.
Qualitative reactions to organic matter
The presence of alkanes is mainly determined by the methodexceptions. If you add potassium permanganate, it will not discolor. These substances burn with a flame of light blue color. Alkenes can be detected by the addition of bromine water or potassium permanganate. Both of these substances discolor when interacting with them. The presence of phenol can also be determined by adding a solution of bromine. At the same time it will discolor and precipitate. In addition, the presence of this substance can be identified using a solution of ferric chloride, which, when interacting with it, will give a violet-brown color. Qualitative reactions for organic substances of the class of alcohols consist in adding sodium to them. In this case, hydrogen is released. The burning of alcohols is accompanied by a light blue flame.
Glycerin can be detected using hydroxidecuprum. At the same time, glycerates are formed, which give the solution a cornflower-blue color. The presence of aldehydes can be determined with the aid of Argentum oxide. As a result of this reaction, pure Argentum is released, which precipitates.
There is also a qualitative response toaldehydes, which is carried out using copper hydroxide. For its implementation it is necessary to heat the solution. At the same time, he must change color first from blue to yellow, then to red. Proteins can be detected using nitric acid. As a result, a yellow precipitate appears. If you add cuprate hydroxide, it will be purple. Qualitative reactions to organic substances of the class of acids are carried out with the help of litmus or ferric chloride. In both cases, the solution changes its color to red. If you add sodium carbonate, carbon dioxide will be released.
Qualitative reactions to cations
They can be used to determine the presence in the solution.ions of any metals. Qualitative reactions to acids consist in identifying the H + cation, which is part of them. This can be done in two ways: with the help of litmus or methyl orange. The first in an acidic environment changes its color to red, the second to pink.
The lithium, sodium and potassium cations can be distinguished bytheir flame. The first ones are red, the second ones are yellow, the third ones are purple flames. Calcium ions are detected by adding carbonate solutions, resulting in a white precipitate.
Qualitative reactions to anions
The most common of these is identifying OH-,as a result, it is possible to find out if bases are present in the solution. For this we need indicators. This is phenolphthalein, methyl orange, litmus. The first in such an environment becomes crimson, the second - yellow, the third - blue.
