There are three classes of complex inorganic compounds: oxides, hydroxides (these include acids and bases), as well as salts. Many metals and non-metals can form oxides, hydroxides, and also be part of acid residues. So, phosphorus is included in the acid residue of PO 4 . There are several varieties of phosphorus oxide. Accordingly, there are various hydroxides of it, which are formed from these oxides. The highest phosphorus hydroxide is phosphoric acid. In this article, we will consider the physical and chemical properties of this element and its compounds, as well as talk about its prevalence in nature and other interesting facts.
Physical properties of phosphorus
It can exist in a variety of variations. Phosphorus is a substance that consists of one chemical element. Its atoms do not combine into molecules. The formula of phosphorus is R. However, depending on the structure of the crystal lattice, this element can exist in the form of three substances.
The most common is white phosphorus - it has a waxy structure and high toxicity. The melting point of this substance is forty-four degrees Celsius, and the boiling point is two hundred eighty degrees. When this material is rubbed, it ignites very quickly, therefore they cut it only by placing it in an aqueous medium. If for a long time it is heated at a temperature of two hundred and fifty degrees Celsius, it turns into red phosphorus. This substance is presented in the form of a brown-red powder. Red phosphorus, unlike white, is not poisonous.
The most stable form of existence of this element can be called black phosphorus, which according to some external signs is similar to metal: it has a peculiar luster, has high hardness, electrical and thermal conductivity.
In terms of chemistry
Phosphorus is a chemical element that is in the fifth group and third period in the periodic table. From this we can conclude that its valency is five. In addition, it can be seen from the periodic system that the phosphorus element has an atomic mass equal to thirty-one grams per mole. This means that 1 mole of substance will weigh 31 one gram. Considering the chemical properties of phosphorus, we will talk about its reactions with simple as well as complex compounds.
Interactions with simple substances
The first thing you need to pay attention to is the oxidation of phosphorus. This is his reaction with oxygen. As a result, two different substances can be formed - everything will depend on the proportions of these components.
The first option is that two moles of phosphorus trioxide are formed from four moles of phosphorus and three moles of oxygen. You can record such a chemical interaction using the following equation: 4P + 3O 2 = 2P 2 O 3 .
The second option is the formation of four moles of phosphorus and five moles of oxygen, two moles of phosphorus pentoxide. This reaction can be expressed using the following equation: 4 + 5 2 = 2 2 5 .
In both chemical reactions, significant light emission occurs. In addition, phosphorus can interact with such simple substances as metals, halogens (fluorine, iodine, bromine, chlorine), sulfur. This chemical element is capable of exhibiting both reducing and oxidizing properties. An example of interaction with halogens is chlorination. It occurs in two stages. The first is the formation of two moles of phosphorus trichlorate from two moles of the considered non-metal and three moles of chlorine. This interaction can be expressed using the following equation: 2P + 3Cl 2 = 2PCl 3 .
The second stage of this process is the addition of chlorine atoms to the phosphorus trichlorate already obtained. So, when one mole of the latter is added to the same amount of chlorine, one mole of phosphorus pentachlorate is formed. We write the equation of this reaction in this way: PCl 3 + Cl 2 = PCl 5 .
The patterns of interaction of phosphorus with metals can be considered on such an example. If we take three moles of potassium and one mole of phosphorus, we get one mole of potassium phosphide. This kind of process can be written using the following reaction equation: 3K + P = K 3 R.
Interaction with complex substances
Complex chemical compounds with which phosphorus is able to react include acids and salts. Let us describe in order the features of the contact of the element under consideration with these groups of chemicals.
Phosphorus and Acids
Among all others, the interaction of phosphorus and nitric acid is especially notable. To carry out this kind of reaction, it is necessary to take the following components: phosphorus in the amount of three moles, five moles of nitric acid, and also water - two moles. As a result of this chemical interaction, we obtain the following products: phosphoric acid and nitrogen oxide. The equation of this reaction is written as follows: 3P + 5HNO 3 + 3H 2 O = 3H 3 PO 4 + 5NO.
Phosphorus and salts
Such chemical interactions can be considered by the example of the reaction of the considered nonmetal with cuprum sulfate. To carry out this process, it is necessary to take two moles of phosphorus, five moles of copper sulfate, eight moles of water. As a result of the interaction of these substances, we obtain the following chemical compounds: sulfate acid in an amount of five moles, pure copper - the same amount, and phosphoric acid - two moles. This process can be written in the form of the following equation: 2P + 5CuSO 4 + 8H 2 O = 5H 2 SO 4 + 5Cu + 2H 3 PO 4 .
Getting this non-metal
In industry, the substance in question is obtained from a chemical compound such as calcium phosphate. To do this, the following chemical reaction is carried out: the indicated salt is mixed with sand (silicon oxide) and carbon in molar proportions of 1: 3: 5, as a result, calcium silicate, phosphorus and chad gas in a molar ratio of 3: 2: 5 are obtained.
Phosphorus Compounds and Their Properties
The most common of the compounds of this non-metal is phosphorus hydroxide. It can be of several types, depending on the oxide from which it is formed. Phosphorus hydroxide can be obtained by carrying out a chemical reaction between its oxide and water. Thanks to such reactions, various types of substances are formed. Thus, hydroxide (3) can be obtained from trioxide, and phosphorus hydroxide (5) from pentoxide. These substances have acidic properties and are capable, in turn, of reacting with metals, salts, bases, etc.
The highest phosphorus hydroxide is phosphoric acid. It is oxygen-containing and tribasic. Its formula is H 3 RO 4 .
Basic chemical properties
Phosphorus hydroxide, the formula of which is given above, is able to react with both simple and complex substances. Consider these processes in more detail.
Reactions of phosphoric acid with metals
Like other chemical compounds of this class, phosphorus hydroxide is able to interact with metals. During this process, a substitution reaction occurs in which metal atoms displace hydrogen atoms, thereby forming salt and hydrogen, which is released into the air as a gas with an unpleasant odor. In order for this reaction to be possible, the metal must be located to the left of hydrogen in the electrochemical series of activity. That is, substances such as copper, silver and others like them are not able to react with phosphoric acid, because due to their low chemical activity they will not be able to displace hydrogen atoms from their compounds.
As an example, consider aluminum. When two moles of this element are added to two moles of phosphorus hydroxide, we obtain aluminum phosphate and hydrogen in the amount of 2 and 3 moles, respectively. The equation of this reaction is written as follows: 2Al + 2H 3 PO 4 = 2AlPO 4 + 3H 2 .
Interaction with the grounds
Phosphorus hydroxide, like many other acids, can enter into chemical reactions with bases. Such processes are called metabolic reactions. As a result, a new hydroxide is formed, as well as a new acid. Such reactions can be carried out only if one of the products obtained is insoluble in water, that is, precipitates, evaporates in the form of gas, or is water or a very weak electrolyte.
Phosphoric acid and salts
In this case, an exchange reaction also occurs. As a result, you can get a new acid and salt. In order for this kind of reaction to take place, the rule that was described just above must also be observed.
The use of phosphorus and its compounds in industry
First of all, the compounds of this chemical element are used to make a mixture that is applied to the side surface of matchboxes. The match heads themselves are also treated with a phosphorus mixture.
The pentoxide of this non-metal is widely used as a dehydrator of gases. It is also used in the chemical industry in order to obtain phosphorus hydroxide, the formula and properties of which were discussed above. In addition, it is used in the manufacture of glass.
Phosphorus hydroxide is also used in many industries. First of all, it is used in the manufacture of fertilizers. This is due to the fact that phosphorus is simply vital for plants. Therefore, there are a number of different fertilizers that are made on the basis of the connection of the considered non-metal. For these purposes, substances such as calcium phosphate are used. Salt is used as fertilizer in ground form. In addition, ordinary and double superphosphate are used for this. Ammophos and nitroammophos can also serve as fertilizers. In addition to all of the above, phosphorus salts or hydroxide are used as a reagent to determine the presence of silver compounds in the solution. So, add the substance, which includes the acid residue of PO 4 , to the solution. If salts or silver hydroxide are present in the latter, a saturated yellow precipitate will precipitate. This is argentum phosphate having the following chemical formula: AgNO 3 .
The structure of the phosphorus atom
As you know, all atoms are composed of a nucleus and electrons orbiting around it. The nucleus contains protons and neutrons. Electrons have a negative charge, protons have a positive charge, and neutrons have a zero charge. The ordinal number of phosphorus in the periodic table is fifteen. From this we can conclude that there are fifteen protons in its nucleus. If the atom is neutral, not an ion, then there are as many electrons as there are protons. That is, in the case of phosphorus, there are fifteen of them.
If one of the electrons leaves its orbit, the atom will turn into a positively charged ion, that is, a cation. If one electron joins, a negatively charged ion is formed - the anion.
In the periodic system of chemical elements, one can see that phosphorus belongs to the third period. From this it is clear that around the nucleus there are three orbits on which electrons are evenly distributed. The first has two, the second has eight electrons, and the third has five.
Prevalence in nature
Mass fraction of phosphorus in the earth's crust is 0.08%. It is not a very common chemical element in nature. However, there is a whole group of minerals that include phosphorus. These are apatites, as well as phosphorites. The most common of the first group is fluorapatite. Its chemical formula is as follows: 3Ca 3 (PO4) 2 • CaF 2 . It comes in transparent, green and turquoise hues. Among phosphorites, calcium phosphate is most common, having the following chemical formula: Ca 3 (PO4) 2 . In addition, phosphorus compounds are found in the tissues of various living organisms.
The role of phosphorus and its compounds in nature and the body
This chemical element is very important for the normal functioning of almost all organs and their systems. First of all, uninterrupted kidney function is impossible without it. This element takes part in the metabolic processes of the body. It also contributes to the speedy tissue regeneration. Without it, some vitamins simply cannot be activated in order to benefit the body - that is why phosphorus is often added to almost all vitamin preparations as an additional component. In addition, it is one of the chemical elements that ensure the normal functioning of the heart. He, in addition to all of the above, is involved in the process of cell division, therefore, without this trace element life on Earth is impossible.
Regulation of the water-salt balance is another function that is performed in the body by the compounds of the non-metal considered in this article. In addition, it is one of the main components of bone and muscle tissue. A large percentage of it is contained in the teeth. Among other things, it is also worth noting that phosphorus is involved in ensuring the normal functioning of the nervous system. Symptoms of a deficiency in the body of the trace element are as follows: increased fatigue, poor performance, disturbances in the nervous system (neurosis, hysteria, etc.), too frequent colds, exhaustion of the heart muscle, pain in bones and muscles, and very poor appetite. To avoid such a thing as a lack of phosphorus in the body, you need to know what products it contains.
First of all, among foods rich in the chemical element in question, fish should be distinguished. A particularly high concentration of phosphorus is observed in species such as sturgeon, mackerel, horse mackerel, tuna, sardine, capelin, pollack, smelt. In addition, the trace element considered in this article is found in crab meat, shrimp, and also in dairy products such as cottage cheese, processed cheese, and feta cheese.
conclusions
Phosphorus, although it is not a very common chemical element on the planet, is of great importance both from an industrial and biological point of view. He and his compounds, in particular phosphorus hydroxide, are used in the manufacture of various products. The article also described the properties of phosphorus hydroxide (phosphoric acid) and the features of its interaction with metals, bases and salts.