What is Phosphide?

Very simply, phosphide is a compound of phosphorus of a binary nature. It has a more electropositive element or group of elements in it. When in any chemical compound phosphorous is combined or used with metal, the phosphide ion is always P3-. The phosphides of all the metals of the periodic table are known. The phosphides of these metals show different types of physical and chemical properties.

Phosphides can be prepared in various ways, one of which is by heating any metal of stoichiometric amount with red phosphorous at high temperatures in a chemically inactive or inert environment. This process also works if the process is conducted inside a vacuum.

Phosphides can be of many different types with their own physical and chemical properties. This is the reason why phosphides can not be appropriately placed in classes. With the basic knowledge of what phosphides are, let’s learn about the different types of phosphides.

What is Silver Phosphide?

The molecular formula of silver phosphide is Ag3P. This compound is made using silver and phosphide (3-). The molecular weight of silver phosphide is 354.578 g/mol. The IUPAC name of the compound is trisilver, phosphorous(3). This compound is canonicalized with a count of 4 heavy atoms and 4 covalently-bonded units.

What is Copper Phosphide?

Copper phosphide is a product of copper and phosphorous that does not react with water. This compound is a phosphide of copper. The molecular formula of copper phosphide is CU3P. This compound is yellowish-grey in colour with a brittle crystalline structure, and when this compound is put under ultraviolet light, it is known to show fluorescence.

CU3P can be created photochemically with ultraviolet radiation. The process would involve irradiating cupric hypophosphite with ultraviolet radiation. It can also be created by a reaction of red phosphorous with a copper-rich compound inside a reverberatory furnace or inside a crucible. This compound is known for being a very good deoxidizer of copper.

What is Cadmium Phosphide?

The chemical formula of cadmium phosphide is Cd3P2. Cadmium phosphide is a chemical compound that is inorganic in nature. It has the appearance of white-bluish or grey, and it works as a semiconductor material with a 0.5 eV bandgap. This compound is used to produce pesticides, parts of laser diodes, and high-frequency and high-power electronic goods.

The reaction of cadmium and phosphorus creates this compound. There are no special environments required for the creation of this compound. This compound is of crystalline nature, and at room temperature, it is found in tetragonal form. 

Cadmium phosphide is one of the main reasons for cadmium poisoning. This compound is hazardous to human health as it is very poisonous if swallowed. The reaction of gastric acids with this compound creates phosphine gas which is deadly for human beings. This compound is also carcinogenic in nature, making it more harmful to human beings.

What is Aluminium Phosphide?

Aluminium phosphide is an inorganic compound; the chemical formula of this compound is AlP. This compound is highly toxic to human beings and is used as a semiconductor material and a fumigant. This compound appears to be green-grey-yellow in colour and is present in powder form. Special care needs to be taken to ensure that this compound is not exposed to moisture when it is being prepared. Exposure to moisture would lead to the generation of phosphine gas which is highly toxic.

Al phosphide is used as pesticides, insecticide, and rodenticide; it is highly toxic and can even lead to ignition or explosion if phosphine gas is released. When sold, this pesticide is balanced with ammonia to reduce the possibility of combustion or explosion. Aluminium phosphide is available in the market through upl aluminium phosphide tablets that are used for the purpose of protecting cereal grain from pests, insects, and rodents.

There are different types of metal phosphide, most of which are highly toxic in nature and need judicious use with special precautions to ensure no accidental deaths due to the compound. Aluminium phosphide is often used in suicide cases; committing suicide by aluminium phosphide is common in India.

These are some of the examples of types of phosphides; there are more examples, such as lead phosphide and phosphide aluminium.

Solved Examples

Q1: What is the Value of the Phosphide Ion When Combined with Metal?

A) P3-

B) P4

C) P1

D) P2+

Answer: A) P3+


Q2: Ag3p is the Molecular Formula of Which Compound?

A) Aluminium Phosphide

B) Copper Phosphide

C) Silver Phosphide

D) Cadmium Phosphide

Answer: C) Silver Phosphide

Q3: Which Compound is Found in a Tetragonal Form at Room Temperature?

A) Silver Phosphide

B) Cadmium Phosphide

C) Aluminium Phosphide

D) Copper Phosphide

Answer: B) Cadmium Phosphide.

FAQs (Frequently Asked Questions)

Q1: What is the Use of Phosphides?

Answer: Phosphides are generally used for one of two things. It is either used as a semiconductor material that is used for the production of high-power and high-frequency electronic goods. Or it is used as a pesticide, insecticide, and rodenticide most commonly used for the protection of cereal grains. The most common pesticide from phosphide is aluminium phosphide that can both be used as a fumigant and an oral pesticide. Aluminium phosphide is sold as tablets or pellets that are mixed with food for the removal of rodents and other small insects and pests. The phosphide tablet reacts in the stomach of the rodent with the gastric acids present there and gives out phosphine gas which causes the death of the rodents as it is highly toxic.

Q2: What is Aluminium Phosphide Made of, and is Phosphide a Metal?

Answer: Aluminium phosphide is an inorganic compound that has the chemical formula of AlP. Aluminium phosphide is synthesized from a combination of various elements 4Al+P4 = 4AlP. This process needs to be done under strict supervision to ensure that the compound is not exposed to moisture. Exposure to moisture would lead to the generation of phosphine gas which is highly toxic in nature.

Phosphides rich in a metal show metallic properties; the phosphides that are rich in metal are hard and brittle in nature with high melting points and chemical inertness. These properties are similar to metallic properties, and phosphides that have these properties appear similar to metals. Such phosphides also have good conductivity to electricity and high thermal conductivity.