Sodium phosphate salt formula. Sodium phosphate: description, application, effects on the body. Converting sodium phosphates to phosphoric anhydride
| Sodium orthophosphate | |
| data are given according to the edition Chemical encyclopedia. In five volumes. / Ed. I.L. Knunyants. - M .: Great Russian Encyclopedia, 1992. - T. 3. - S. 367-368. - ISBN 5-85270-008-8. | |
| General | |
|---|---|
| Systematic Name |
sodium orthophosphate |
| Chem. formula | Na3PO4 |
| Physical properties | |
| State | solid crystalline substance |
| impurities | water, is part of the crystalline hydrates of sodium orthophosphates |
| Molar mass | 163.94067 g/mol |
| Density | anhydrous - 2.536; crystalline hydrate - 1.62 g / cm³ |
| Thermal Properties | |
| T. melt. | anhydrous - 1340; crystalline hydrate - 73.3÷76.7 °C |
| Enthalpy of formation | anhydrous -1922.8; crystalline hydrate -4471.6 kJ/mol |
| Chemical properties | |
| Solubility in water | in terms of anhydrous 12.1 (0°C); 94.6(100°C) |
| Data is based on standard conditions (25 °C, 100 kPa) unless otherwise noted. | |
Sodium phosphate (sodium orthophosphate)- sodium salt of phosphoric acid with the chemical formula Na 3 PO 4 .
Description
Sodium phosphate - salt. White, hygroscopic. Melts without decomposition, thermally stable. Let's well dissolve in water, it is hydrolyzed on anion, creates strongly alkaline environment in solution. Reacts in solution with zinc and aluminum. Enters into ion exchange reactions. In the presence of water, it forms a crystalline hydrate with the general formula Na 3 PO 4 × 12H 2 O.
Receipt
Application
The use of sodium phosphate in laundry detergents is banned in many countries to reduce eutrophication of water bodies.
In food products (food additive E339 (iii)) it is not sodium phosphate that is used, but dihydrogen phosphate as a baking powder for dough (when interacting with baking soda) and an emulsifier for processed cheese, sausage, condensed milk.
It is used for discoloration of glass during its melting.
see also
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An excerpt characterizing sodium orthophosphate
The Countess wept when she heard the news of the fire in Moscow. Natasha, pale, with fixed eyes, sitting under the icons on the bench (in the very place where she sat down when she arrived), did not pay any attention to her father's words. She listened to the incessant groan of the adjutant, heard through three houses.- Oh, what a horror! - said, come back from the yard, cold and frightened Sonya. - I think all of Moscow will burn, a terrible glow! Natasha, look now, you can see it from the window from here, ”she said to her sister, apparently wanting to entertain her with something. But Natasha looked at her, as if not understanding what she was being asked, and again stared with her eyes at the corner of the stove. Natasha has been in this state of tetanus since this morning, from the very time that Sonya, to the surprise and annoyance of the countess, for no reason at all, found it necessary to announce to Natasha about the wound of Prince Andrei and about his presence with them on the train. The countess was angry with Sonya, as she rarely got angry. Sonya cried and asked for forgiveness, and now, as if trying to make amends for her guilt, she did not stop caring for her sister.
“Look, Natasha, how terribly it burns,” said Sonya.
- What is on fire? Natasha asked. – Oh, yes, Moscow.
And as if in order not to offend Sonya by her refusal and to get rid of her, she moved her head to the window, looked so that she obviously could not see anything, and again sat down in her former position.
- Didn't you see it?
“No, really, I saw it,” she said in a pleading voice.
Both the countess and Sonya understood that Moscow, the fire of Moscow, whatever it was, of course, could not matter to Natasha.
The count again went behind the partition and lay down. The countess went up to Natasha, touched her head with her upturned hand, as she did when her daughter was sick, then touched her forehead with her lips, as if to find out if there was a fever, and kissed her.
- You are cold. You're all trembling. You should go to bed,” she said.
- Lie down? Yes, okay, I'll go to bed. I'm going to bed now, - said Natasha.
Since Natasha was told this morning that Prince Andrei was seriously wounded and was traveling with them, she only in the first minute asked a lot about where? as? is he dangerously injured? and can she see him? But after she was told that she was not allowed to see him, that he was seriously injured, but that his life was not in danger, she obviously did not believe what she was told, but convinced that no matter how much she said, she would be answer the same thing, stopped asking and talking. All the way, with big eyes, which the countess knew so well and whose expression the countess was so afraid of, Natasha sat motionless in the corner of the carriage and was now sitting in the same way on the bench on which she sat down. She was thinking about something, something she was deciding or had already decided in her mind now - the countess knew this, but what it was, she did not know, and this frightened and tormented her.
- Natasha, undress, my dear, lie down on my bed. (Only the countess alone was made a bed on the bed; m me Schoss and both young ladies had to sleep on the floor in the hay.)
“No, mom, I’ll lie down here on the floor,” Natasha said angrily, went to the window and opened it. The groan of the adjutant was heard more distinctly from the open window. She stuck her head out into the damp night air, and the countess saw her thin shoulders tremble with sobs and beat against the frame. Natasha knew that it was not Prince Andrei who was moaning. She knew that Prince Andrei was lying in the same connection where they were, in another hut across the passage; but this terrible unceasing groan made her sob. The Countess exchanged glances with Sonya.
"Lie down, my dear, lie down, my friend," said the countess, lightly touching Natasha's shoulder with her hand. - Well, go to bed.
“Ah, yes ... I’ll lie down now, now,” said Natasha, hastily undressing and tearing off the strings of her skirts. Throwing off her dress and putting on a jacket, she tucked her legs up, sat down on the bed prepared on the floor and, throwing her short, thin braid over her shoulder, began to weave it. Thin long habitual fingers quickly, deftly took apart, weaved, tied a braid. Natasha's head, with a habitual gesture, turned first to one side, then to the other, but her eyes, feverishly open, fixedly stared straight ahead. When the night costume was over, Natasha quietly sank down on a sheet spread on hay from the edge of the door.
“Natasha, lie down in the middle,” said Sonya.
“No, I’m here,” Natasha said. "Go to bed," she added with annoyance. And she buried her face in the pillow.
The countess, m me Schoss, and Sonya hurriedly undressed and lay down. One lamp was left in the room. But in the yard it was bright from the fire of Maly Mytishchi, two miles away, and the drunken cries of the people were buzzing in the tavern, which was broken by the Mamon Cossacks, on the warp, in the street, and the incessant groan of the adjutant was heard all the time.
For a long time Natasha listened to the internal and external sounds that reached her, and did not move. At first she heard her mother's prayer and sighs, the creaking of her bed under her, the familiar whistling snore of m me Schoss, Sonya's quiet breathing. Then the Countess called Natasha. Natasha did not answer her.
“He seems to be sleeping, mother,” Sonya answered quietly. The Countess, after a pause, called again, but no one answered her.
Soon after, Natasha heard her mother's even breathing. Natasha did not move, despite the fact that her small bare foot, knocked out from under the covers, shivered on the bare floor.
As if celebrating the victory over everyone, a cricket screamed in the crack. The rooster crowed far away, relatives responded. In the tavern, the screams died down, only the same stand of the adjutant was heard. Natasha got up.
- Sonya? are you sleeping? Mother? she whispered. Nobody answered. Natasha slowly and cautiously got up, crossed herself and carefully stepped with her narrow and flexible bare foot on the dirty cold floor. The floorboard creaked. She, quickly moving her feet, ran like a kitten a few steps and took hold of the cold bracket of the door.
It seemed to her that something heavy, evenly striking, was knocking on all the walls of the hut: it was beating her heart, which was dying from fear, from horror and love, bursting.
She opened the door, stepped over the threshold and stepped onto the damp, cold earth of the porch. The chill that gripped her refreshed her. She felt the sleeping man with her bare foot, stepped over him and opened the door to the hut where Prince Andrei lay. It was dark in this hut. In the back corner, by the bed, on which something was lying, on a bench stood a tallow candle burnt with a large mushroom.
In the morning, Natasha, when she was told about the wound and the presence of Prince Andrei, decided that she should see him. She didn't know what it was for, but she knew that the date would be painful, and she was even more convinced that it was necessary.
All day she lived only in the hope that at night she would see him. But now that the moment had come, she was terrified of what she would see. How was he mutilated? What was left of him? Was he like that, what was that unceasing groan of the adjutant? Yes, he was. He was in her imagination the personification of that terrible moan. When she saw an indistinct mass in the corner and took his knees raised under the covers by his shoulders, she imagined some kind of terrible body and stopped in horror. But an irresistible force pulled her forward. She cautiously took one step, then another, and found herself in the middle of a small cluttered hut. In the hut, under the images, another person was lying on benches (it was Timokhin), and two more people were lying on the floor (they were a doctor and a valet).
Sodium phosphate (colloquial, correct: sodium phosphate, orthophosphate, bone phosphate or Na 3 PO 4) is a white hygroscopic medium salt, thermally stable and melting without decomposition (at temperatures of 250 degrees and above). It dissolves in water, creating a highly alkaline environment.
Sodium phosphate is obtained by the action of alkali on (neutralization), during the dehydration of sodium hydroorthophosphates.
Used as emulsifiers and pH regulators, as well as anti-caking agents. Sodium phosphate is used by manufacturers. Triphosphate is especially often used, which can be up to 50% in powders. For (elimination of rigidity) dehydrotized substances are used, which form a complex with a number of metals (magnesium, calcium, barium, etc.). Sodium phosphate (technical, under the brand name "B") is used in the manufacture of glasses, paints, and in the enrichment of ores. But Na 2 HPO 4 .12H 2 O (food, under the brand name "A") is used mainly in the food industry as a baking powder. It improves the consistency of condensed milk, cheeses, sausages. Sodium phosphate is used for electrophoresis (electrolytic processes) and in photography (as a developer component).
Consider orthophosphates in more detail.
Sodium tripolyphosphate is produced under two markings: "A", "B". Packed only in special containers MKR-1, transported in equipped (special) mineral wagons. Shelf life without limitation.
Trisodium phosphate (sodium phosphate, trisubstituted) is used in the food, pulp and paper industries, in the energy sector, in the production of powders, cleaning pastes, dishwashing detergents, and as a surfactant in the production of cement. When drilling, it is included as a polymer additive. Trisodium phosphate perfectly degreases the surface of any equipment, so it is in demand for flushing. It looks like scales (crystals) with alkaline properties, non-flammable. It ranks second in terms of its effect on the human body.
Quite a logical question: "With such a wide use, does sodium phosphate harm our body?"
An antioxidant (on the labels it is listed as E-300 (and up to E-339) allows you to preserve color, avoid bitterness and protects against oxidation. It can be either a natural compound (vitamin E, ascorbic acid familiar to everyone), or chemically synthesized, not found in nature Added to emulsions containing oils (e.g. mayonnaise, ketchup) In addition to its emulsifier and stabilizer properties, Na 3 PO 4 is a water-retaining agent, complexing agent, stabilizer For example, in high-volume baking (bakery, bakery) is extremely important high dough rise, and with a porous and light structure.Here, between and a salt of phosphoric acid, it just gives the desired effect in the end.Modification E-450 (SAPP, sodium pyrophosphate) is especially popular.This baking powder allows for excellent dough rise (maximum in comparison with analogues), remaining even after baking. Added to muffins, cakes, gingerbread, pizza, cakes. Recommended for obtaining almost any o dough (frozen yeast, whipped, crumbly shortbread).
The buffer properties of E-450, as well as the ability to bind calcium, are used in dairies. Pyrophosphates have a specific effect on casein - it opens, swells and acts as an emulsifier, which is convenient when preparing puddings, imitation dairy products, and desserts. Condensed milk, obtained by extracting water, also does not do without the salt-stabilizer DSP (disubstituted sodium phosphate).
In the meat industry, thanks to the emulsifiers we are discussing, they significantly increase the overall yield of products while stabilizing the consistency and improving the color.
The use of products containing sodium phosphates (or prepared with their use) is best limited, since the rapid binding of calcium leads to a deficiency of the latter in the body. In addition, this substance is part of laxatives, so an excessive amount of sausage can disrupt the digestive tract.
DEFINITION
Under normal conditions sodium phosphate is a hygroscopic, thermally stable white powder (Fig. 1), the crystals of which melt without decomposition.
It dissolves well in water (hydrolyzes), creating an alkaline environment.
Rice. 1. Sodium phosphate. Appearance.
The main characteristics of sodium phosphate are given in the table below:
Obtaining sodium phosphate
Laboratory methods for obtaining sodium phosphate involve the action of phosphoric acid on sodium salts (1) or sodium hydroxide (2):
3Na 2 CO 3 + 2H 3 PO 4 = 2Na 3 PO 4 + 3CO 2 + 3H 2 O (1);
3NaOH + H 3 PO 4 = Na 3 PO 4 + 3H 2 O (2).
Chemical properties of sodium phosphate
Sodium phosphate is an average salt formed by a strong base - sodium hydroxide (NaOH) and a weak acid - orthophosphoric (H 3 PO 4). Hydrolyzes in aqueous solution. Hydrolysis proceeds through the anion (theoretically, the second and third steps are possible). The presence of OH anions indicates the alkaline nature of the medium.
First stage:
Na 3 PO 4 ↔ 3Na + + PO 4 3-;
3Na + + PO 4 3- + HOH ↔ HPO 4 2- + 3Na + + OH - ;
Na 3 PO 4 + HOH ↔ Na 2 HPO 4 + NaOH.
Second step:
Na 2 HPO 4 ↔ 2Na + + H 2 PO 4 - ;
2Na + + H 2 PO 4 - + HOH ↔ NaHPO 4 + 2Na + + OH - ;
Na 2 HPO 4 + HOH ↔ NaHPO 4 + NaOH.
Third step:
NaHPO 4 ↔ Na + + PO 4 3-;
Na + + PO 4 3- + HOH ↔ H 3 PO 4 + Na + + OH -;
NaHPO 4 + HOH ↔ H 3 PO 4 + NaOH.
Sodium phosphate is characterized by all the properties of salts:
- interaction with strong mineral acids
Na 3 PO 4 + 3HCl \u003d 3NaCl + H 3 PO 4;
- interaction with salts, as a result of which one of the reaction products is a water-insoluble compound
2Na 3 PO 4 + 3Li 2 SO 4 \u003d 2Li 3 PO 4 ↓ + 3Na 2 SO 4;
- decomposition on heating
Application of sodium phosphate
Sodium phosphate has found application in the food industry - additive E542, used in the production of pasta, fermented milk products, meat and culinary semi-finished products. It is also an ingredient in toothpastes and some cosmetic preparations.
Examples of problem solving
EXAMPLE 1
| Exercise | What mass of phosphorus (V) oxide is formed during the reaction of thermal decomposition of sodium phosphate weighing 200 g? |
| Solution | We write the reaction equation for the thermal decomposition of sodium phosphate: 2Na 3 PO 4 \u003d P 2 O 5 + 3Na 2 O. Calculate the amount of sodium phosphate substance (molar mass - 164 g / mol): n(Na 3 PO 4) \u003d m (Na 3 PO 4) / M (Na 3 PO 4); n (Na 3 PO 4) = 200/164 = 1.22 mol. According to the reaction equation n(Na 3 PO 4) :n(P 2 O 5) = 2:1. Then the number of moles of phosphorus oxide (V) will be equal to: n (P 2 O 5) \u003d ½ × n (Na 3 PO 4) \u003d ½ × 1.22 \u003d 0.61 mol. Let's find the mass of the resulting phosphorus (V) oxide (molar mass - 284 g / mol): m (P 2 O 5) \u003d n (P 2 O 5) × M (P 2 O 5) \u003d 0.61 × 284 \u003d 173.24 g. |
| Answer | The mass of phosphorus (V) oxide formed is 173.24 g. |
Salts derived from sodium hydroxide and phosphoric acid are collectively called sodium phosphates. This nutritional supplement is completely synthetic and does not occur in nature in any form.
In food, it is most commonly used as an antioxidant and preservative, although it also has emulsifier and stabilizer properties. In addition, the substance also acts as an acidity regulator, as it affects the establishment and maintenance of a certain level of acidic environment in the product. It also has a moisture-retaining effect.
Having met the E339 code in the composition of the selected food, the buyer can determine for himself that the product has been treated with sodium phosphates, and decide whether it is worth buying and using it. According to international standards and norms, the substance belongs to food additives of a low degree of danger.
Methods for obtaining sodium phosphates in the laboratory
To date, there are several technologies for the extraction of sodium phosphates: using thermal phosphoric acid, superphosphate or acid obtained by the sulfuric acid method.
One of the methods involves carrying out a neutralization reaction of 25% phosphoric acid with a solution of soda ash. The resulting mixture is filtered, evaporated to a certain density and crystallized. If phosphoric acid has a saturation of more than 40%, the neutralization reaction is carried out at a temperature of 85-95 degrees Celsius.
Superphosphates are treated with sodium sulfate solution. The resulting substance is monosodium phosphate, which is filtered in an acidic solution from the insoluble residue and the released calcium sulfate, and then also evaporated or granulated in a spray dryer.
Chemical properties of a substance
The additive is in the form of a white powder in granules or crystals. It is not sensitive to thermal effects and is highly soluble in.
Substance E339 is used as a thickener, as it has the property of regulating the viscosity of the mixture, improving its texture. As a stabilizer, the E339 additive is involved in the formation of the consistency of the product, contributes to its improvement and preservation unchanged, protects food from burning during heat treatment. Also, sodium phosphates have found their use as emulsifiers, since one of their properties is the ability to create mixtures together with initially immiscible substances, for example, a mixture of oil and water.
Varieties of food additive
In the food industry, these types of sodium phosphates are commonly used;
- sodium orthophosphate 1-substituted (E339i);
- sodium orthophosphate 2-substituted (E339ii);
- 3-substituted sodium orthophosphate (E399iii).
Their chemical formulas differ from each other, but the substances have a similar effect. Therefore, if you see one of these designations on the packaging of a product, you can be sure that sodium phosphates were used in it.
Application in production
The main purpose of the substance is to improve the properties of food products, therefore the food industry is the main “consumer” of this component. It can be found in the compositions:
- bakery and confectionery products;
- dairy products and;
- soft drinks;
- dry soups, sauces, pastes, bouillon cubes and other instant products;
- cheeses and;
- meat and fish products;
- dry baking powder and baking mixes;
- biscuits and cakes.
Especially often it is found in sausages and sausages, meat and fish: the substance works as a moisture-retaining component, therefore, in this way it is possible to preserve products without loss of moisture and, accordingly, weight.
In addition, until the 1960s, it was widely used in the production of detergents and powders. However, due to the excess ingress of nitrogen and phosphorus compounds into water bodies, the quality of waste water, which further enters water pipes and is released into the natural environment, began to deteriorate significantly, which could harm the aquatic ecosystem. For this reason, restrictions and prohibitions on the use of the substance in such products began to appear, and today they are practically not used in the manufacture of powders and detergent products.
Sodium phosphates are also used in the pharmaceutical industry - they are added to laxatives, since the substance has the appropriate effect at a certain dosage.
Impact on the human body, possible harm from use
The laxative effect of the substance is known to both physicians and chemists. Products that contain it in their composition should be present in the human diet in a limited amount so as not to provoke a corresponding reaction of the digestive tract.
As for other possible dangers of the E339 food additive, these include the likelihood of diseases of the gastrointestinal tract: gastritis, ulcers, pancreatitis. However, to date, the relationship between substance use and these disorders has not been officially confirmed.
The results of studies conducted on laboratory animals indicate that sodium phosphates contribute to impaired absorption in the body, washing it out of bone tissue and tooth enamel.
In some cases, detergents and powders containing E339 cause allergic reactions in the form of skin rashes and redness.
In children, the use of products with this component in the composition can cause nervous disorders: impaired concentration, aggression, anxiety, hyperactivity, motor anxiety. For them, the amount of food with the addition of E339 should be limited.
According to some unconfirmed reports, sodium phosphates have an oncogenic effect, that is, they can cause oncological diseases of the digestive tract. Other than a possible therapy for constipation, nothing is known to date about the benefits of the substance for human health.
While manufacturers are on the path to reduce the cost of food products, additives with the “E” code, including E339, will be indicated on the labels of a variety of foods. The component is used as an anti-caking agent, emulsifier, antioxidant and thickener: with its help, it improves the taste and texture characteristics of food, while it is a cheap and profitable ingredient for manufacturers.
Sodium phosphates are substances with an extremely low level of danger to humans, their use is permitted in Ukraine, Russia and the countries of the European Union. In addition to the threat of a violation of calcium metabolism in the body, no other information about possible harm to health has yet been officially confirmed. Nevertheless, research on the effects of sodium phosphates on humans continues today.
sodium phosphate or sodium phosphate(English) sodium phosphate) is the common name for a series of sodium salts of phosphoric acids.
Sodium phosphates used in the pharmaceutical and food industries
Historically, each of the compounds of sodium phosphate has several names, both in Russian and in English. Below are some of these names and chemical formulas of the most common sodium phosphates in medicine and the food industry:
Sodium phosphates in medicine
Sodium salts of phosphoric acids in medicine are used as laxatives, as part of antacids, as well as to maintain the mineral balance and acid-base balance of the blood. In addition, they are often included in the composition of drugs as excipients.The laxative effect of sodium phosphate is based on the increase and retention of fluid in the intestine due to osmotic processes. The accumulation of fluid in the colon leads to increased peristalsis and defecation.
Sodium phosphate compounds have contraindications, side effects and application features, consultation with a specialist is necessary.
Sodium phosphate - food supplement
The composition and requirements for food additives - sodium salts of phosphoric acid are regulated by GOST R 52823-2007. Food additives. Sodium phosphates E339. General technical conditions". This GOST applies to the E339 sodium phosphate food additive, which is 1-substituted (i), 2-substituted (ii) and 3-substituted (iii) sodium salts of orthophosphoric acid (hereinafter referred to as food sodium monophosphates) and intended for use in the food industry . GOST subdivides all food additives E339 - sodium monophosphates into three types:- E339(i), 1-substituted sodium orthophosphate (sodium dihydrogen phosphate)
- E339(ii), 2-substituted sodium orthophosphate (sodium hydrogen phosphate)
- E339(iii), 3-substituted sodium orthophosphate (sodium phosphate).