The phosphorous acid has a formulation for industrial and agricultural uses. It is widely sold around the world and, together with hypophosphorous acid, belongs to the group of diprotic chemical compounds or acids.
Contents
Phosphorous Acid, what is it
It is a chemical compound with properties that allow it to function as a weak reducing agent, slightly weaker than hypophosphorous acid. It is useful in the preparation of phosphorous compounds, where it acts as a necessary element for their manufacture.
Its chemical structure, within the diprotic group, facilitates the donation of 2 protons H+ per molecule when present in an aqueous solution. The phosphorous acid has the following chemical and physical properties:
- Formula of phosphorous acid or formulation: H3PO3.
- Density: 1651 kg/m3 or 1651 g/cm3.
- Molar mass: 82 g/mol.
- Boiling point: 200 °C or 473 K.
- Melting point: 73.6 °C or 347 K.
- pH: 1.3.
- pKa: 7.7.
- Soluble in water: 310 g/100 ml.
- Soluble in alcohol: yes.
- Color:
- Used as a weak reducing agent.
Uses
- Water treatment.
- Production of mineral compounds.
- Treatment for plants and vegetables.
- Reducing agent in chemical analysis.
- Vinyl additive.
It has various applications, but the most common uses of phosphorous acid are for water treatment. This chemical compound makes it possible to produce phosphites, which is also the reaction needed to manufacture potassium phosphite.
Additionally, one of its characteristics is serving as a reducing agent for chemical analysis, with phosphites and phosphorous being very commonly used elements.
Other uses and applications of phosphorous acid are in the industrial sector, where it is part of the range of additives necessary for manufacturing vinyl chloride. This is a colorless, highly unstable gas, but it is currently added to produce PVC. Therefore, phosphorous is also part of this type of material, widely used in homes, commercial premises, and all types of infrastructure that require plastic materials as well as metal coatings.
Relation with hypophosphorous acid
It is also a reducing agent, but unlike phosphorous acid, it is a strong reducing agent. It is necessary for electroplating without electrolysis or mold making.
It is known as hypophosphite or HPA and phosphinic acid, and the hypophosphorous acid has the formula: H3PO2.
It is classified as an oxacid of phosphorus and a hydroxophosphine oxide.
The chemical characteristics and properties of hypophosphorous acid often cause a chemical reaction when it comes into contact with another strong reducing agent, reducing it to phosphine.
When mixed with silver nitrate, it precipitates, forming a white compound that abruptly turns dark.
At the same time, it also reacts with other strong acids such as sulfuric acid. With this, it decomposes, forming sulfur dioxide and sulfur for industrial uses.
Its handling should be done with caution, as indicated in the safety data sheet for hypophosphorous acid, especially if mercury II oxide and mercury nitrate are present, as it is easy for them to react violently, causing an explosion.
The relationship between hypophosphorous acid and phosphoric acid is that the former decomposes to form hydrogen phosphide, also called phosphine, and orthophosphoric acid. To achieve this, the temperature must be raised to a range between 130 and 140 °C.
It is a very corrosive acid for organic tissues. Skin, mucous membranes, and eyes must be protected to avoid permanent damage and sequelae from handling it.
Sale of phosphorous acid
Because it is a corrosive agent, it is necessary to go to chemical industries and online stores with chemical products. Nowadays, buying and shipping it is much easier than a few years ago. The sale of phosphorous acid is worldwide, so you won’t have problems acquiring it in your locality or placing an online order.