An Introduction to Sodium Hexametaphosphate
Also known as Calgon, sodium hexametaphosphate is a chemical compound that consists of a mix of polymeric metaphosphates. It is a hexamer that contains repeated \[(NaPO_{3})\]units. This means that it is a polymer that has six molecular compositions of a monomer. This compound is soluble in water and has a circulation of multiple polyphosphate chain lengths.
This compound forms as a result of a thermal procedure that is formed from monosodium orthophosphate.
What is the Preparation of Sodium Hexametaphosphate?
The compound \[(NaPO_{3})_{6}\], which is also popularly named Calgon, has a specific preparation procedure. The below steps explain it further. The complex can be obtained when monosodium orthophosphate goes through a thermal process or heating. Initially, it generates sodium acid pyrophosphate. The reaction is shown below as:
\[ 2 NaH_{2}PO_{4} \rightarrow Na_{2}H_{2}P_{2}O_{7} + H_{2}O \]
Further, this pyrophosphate gets heated to generate the final complex (NaPO3)6 followed by rapid cooling. The chemical reaction gets depicted below as:
\[ 3 Na_{2}H_{2}P_{2}O_{7} \rightarrow (NaPO_{3})_{6} + 3 H_{2}O \]
What are the Chemical Properties of this Compound?
The boiling point of sodium hexametaphosphate is 1500 degrees Celsius.
It has a molecular weight of 611.7704 g mol-1.
The atomic mass of Calgon is 30.
It has a melting point of 62 degrees Celsius.
The monoisotopic mass of this compound is 611.689651 g/mol.
For sodium hexametaphosphate, the topological polar surface area is calculated at 296 Ų.
When exposed to water-based solutions, this compound can hydrolyse either into sodium trimetaphosphate or sodium orthophosphate.
What are the Physical Attributes of this Compound?
This has a slightly colourless or white appearance in the form of crystals and looks translucent or transparent under the light.
It has no characteristic odour.
It has a refractive index of 1.482
It is soluble in water but not in inorganic solvents.
It has a slightly higher ph value than water, at 8.6
Applications
Sodium hexametaphosphate has various uses in industrial, consumer and agricultural purposes due to its intrinsic properties. Some of these include:
Industrial uses:
To prepare solutions in industries for the production of ceramics, including additives is a mandatory step to obtain a proper fluid paste. Therefore, the compound \[(NaPO_{3})_{6}\] gets used as a dispersing agent in the manufacture of ceramics and enamels.
It has been useful in the paint industry.
It is used to convert pulp into paper due to the nature of phosphates.
It is also used in the food preservation industry since it can keep food fresh for a longer time.
This also is used in toothpaste since it can reduce the formation of tartar in the mouth.
It is used in boilers in industries since it can reduce the hardness of water greatly.
It has wide applications in the ceramics industry.
Agricultural and Consumer Uses:
It also gets used in agricultural chemicals that help in the growth of plants and increase their productivity. It primarily gets applied for non-pesticidal purposes that do not interfere in pests’ interaction.
It also gets used as a water-retaining agent. Due to this property, the complex finds its applications in meat and sausage processing. It enables non-vegetarian foods to last for a long period and reduces their anti-microbial activities.
The compound also acts as a stabiliser for canned fruits, and milk, and it helps in maintaining its natural colour. Apart from these, it gets used in artificial maple syrup, packaged egg whites, fish fillets and salad dressing, etc. It also gets used in beverages to store them for a longer span.
Effects of Calgon
Calgon or Graham’s Salt is a white powdery substance comprising sodium and metaphosphates. Although the chemical compound has wide-scale application in various sectors, yet these have some effects on human beings, and plants due to prolonged exposure.
The following pointers show some of its impacts. Read them to know more.
Calgon can have a negative impact on the surroundings the environment if found in aquatic settings.
It can induce vomiting and diarrhoea if it is inhaled or swallowed.
The compound can also cause headache and dizziness when it gets absorbed by a person for short durations.
It also causes fever, tiredness and low blood pressure when it gets injected in a body for a short span.
The complex can also cause gastrointestinal infection and allergic reactions when someone comes in its exposure for fewer periods.
Prolonged exposure to the compound can result in slower pulse rate, cyanosis and even coma along with acute spasms in the body and wrist.
If anyone comes in close contact with the compound for a larger span, it causes pancreatic cancer. It is capable of increasing cancer-causing cells in the body.
If someone comes in close contact with this compound, it can result in severe eye irritation. However, the severity of the circumstance varies with the prevalent concentration of this substance.
Kidney problems are also an evident side-effect of the compound on a body.
Direct contact of this chemical compound through open wounds, abrasions or lesions can result in damage to sensitive-skinned people.
Loss of essential minerals from the bones can occur due to long-term exposure to the chemical
FAQs on Sodium Hexametaphosphate
1. What is the formula of Calgon?
Calgon is a popular name propounded for the chemical compound sodium hexametaphosphate. The Calgon formula for this compound is Na6P6O18.
2. What are the other common names of Sodium Hexametaphosphate?
The commonly used names of this chemical compound are glassy sodium, Graham’s salt. It is also known as metaphosphoric acid, hexasodium metaphosphate, and hexasodium salt. Besides, it is popularly known as sodium hexametaphosphate Calgon.
3. How harmful is Graham’s salt or Na6P6O18?
The chemical compound Na6P6O18 has both short-term and long-term uses in the body. When tested in the laboratory on animals, it shows kidney swellings, calcium loss from bones, skin irritations and muscular changes in fiber, etc.
4. What is the role of the chemical compound Na6P6O18 in food?
The complex gets used in foods as it acts as a preservative and stabilizer. It plays a key role in improving the food texture as it helps in water binding and retention, thickening, and emulsification. Moreover, it helps to protect the nutrition value of food particles and canned products.
5. What are the side effects of sodium hexametaphosphate?
If this is ingested or inhaled or taken in any way that is not at par with permissible limits, then it can cause significant health problems. The symptoms may appear as headaches, drowsy spells, extreme lethargy, diarrhoea, intense vomiting, irregular heartbeat, problems with blood platelet and cell count and even the risk of strokes. Phosphates are toxic since they can separate calcium from compounds, so if these enter the body, they will start reactions inside the body and lead to problems like systolic acidosis.
6. Is sodium hexametaphosphate used in dog food?
Yes, sodium hexametaphosphate is also added to dog food but not just as a preservative. It is useful for the dental health of dogs. Due to the properties of sodium hexametaphosphate, it can separate and bind itself to calcium that is found in the dental plaque of dogs. Once this bond is formed, it gets carried away by saliva into the body and is ultimately excreted out. This reduces the chances of cavities and gum problems in dogs. In fact, sodium hexametaphosphate is added to toothpaste a lot for this same reason.
7. Can sodium hexametaphosphate be used for patients who are allergic to gluten?
Foods that are preserved with sodium hexametaphosphate can be taken by people who have allergies to gluten, provided that the food itself is gluten-free. This compound is free of gluten, so it should not pose any health risks to people who are allergic to it. Sodium hexametaphosphate is added to a number of foods since it has been approved by FDA as a qualified preservative that does not cause long-term harm to health. it is used mostly for packed and canned goods.
8. Why is sodium hexametaphosphate added to soil?
Sodium hexametaphosphate is a well-known compound used in making various kinds of fertilizers. Since it has phosphates, it has a number of benefits for soil fertility. This is not directly added to soil, of course, but in concentrations when it is mixed in with other compounds, it can increase soil fertility. For soils that have a more clay-like composition, this is used in making sure the clay particles do not stick and sediment together and allow for enough movement of water and air in the soil.
9. How can sodium hexametaphosphate soften water?
One of the prime industrial applications of sodium hexametaphosphate is softening hard water to reuse for industrial uses. This works on the basis of the fact that sodium hexametaphosphate is soluble in water. Calgon by nature is a softening agent because sodium hexametaphosphate forms water-soluble compounds with the cations, such as magnesium and calcium cations. These are present in industrial hard water, and when these compounds react with sodium hexametaphosphate, these cations can be eliminated. This can be used to separate hard water and filter in soft water.
