What is Nitride Ion?

The first question is, what is nitride and its properties. When nitrogen combines with elements such as silicon, boron, any other metals or any element with lower or similar electronegativity than nitrogen, it is known as a nitride. It is a separate class of compound altogether. Nitride, just like carbides, can be separated into three general categories is known as interstitial, ionic and covalent nitrides. Nitride compounds generally contain the nitride ion. Now questions such as what is the formula for nitride, what is the charge of nitride, what is the symbol of nitride are bound to arise. We will answer these questions a bit later. Such compounds usually react with water to turn into the hydroxide or oxide of the metal and ammonia gas. 

Nitride Ion Overview

The question of what is nitride can be explained better by saying that it never comes through an aprotic solution. It is mainly a nitrogen compound. The Ionic radius of nitrides is 140 pm approximately. The oxidation state of nitrogen is -3. Nitride ion is the main iron present in nitrides along with the metal cation. Another question that comes is what is the formula for nitride Ion. The formula for nitride Ion is N-3. Some metal nitrates are very unstable. At the same time, some metal nitrides like those of vanadium, boron, silicon, tantalum, titanium and more are refractory. These are also resistant to earth chemical interactions and are very hard. Uses of nitride are seen in crucibles and abrasives due to hardness.

Preparation of Nitrides

There are three methods for the preparation of nitrides. The first method is where elements directly combine or reaction proceeds at higher temperatures. Calcium nitride synthesis is shown below with the direct combination method.

3Ca + N2 -----> Ca3N2

The second method is a much more feasible one and is by loss of ammonia or NH3. It is done by the thermal breakdown of decomposition of barium amide or any metal amides available.

3Ba(NH2)2 -----> Ba3N2 + 4NH3

The method is also an easy one to proceed within the future. During the surface hardening of metal objects, preferably steel, nitride are also formed. Ammonia when heated to high temperatures between 950 to 1050 Fahrenheit or 500 to 570 Celsius for almost 100 hours starting from minimum 5 hours gives out nitride. But it also depends on the desired hardening form or case's depth.

Reduction of metal oxides are metal halides that also produce nitride. It is another method to prepare nitrides and knows exactly what is a nitride. The process takes place in the presence of gaseous nitrogen. Let's take an example and prepare aluminium nitride with this method.

Al2O3 + 3C + N2 -----> 2AlN + 3CO

Uses of Nitride

There are many uses of nitride, but mainly they are used as insulators. One of the lubricants at high temperatures is hexagonal boron nitride which is extremely hard. The lubricating nature is due to its layered structure. It is akin to molybdenum disulfide. Nitrides are also used for cutting materials and hard coatings. For example, titanium nitride and silicon nitride are used for the same. It is because similar to carbides, nitride has high lattice energy and hence are generally refractory substances. The N-3 ions have a strong attraction with the metal cations. Owing to the large band gaps, nitride behaves like insulators. Blue light emitted from LED lights is due to the excessive bandgap in gallium nitride. Some nitrides like lithium nitride are also used for hydrogen storage purposes as they can absorb hydrogen-like metal oxides.

Ionic Nitrides

The only alkali metal does form a nitride is Lithium. Every alkaline Earth metal forms nitrides. The formula they have is M3N2. These nitrides react with water (hydrolysis) and produce metal hydroxide and ammonia. Ionic Nitrides have a wide range of stability. Be3N2 has a melting point of 2200 degree Celsius, and Mg3N2 at 270 degree Celsius decomposes completely.

Interstitial Nitrides

Transition metals with nitrogen form interstitial Nitrides. Nitrogen atoms occupy holes or spaces in the closely packed lattice of the metal. The formula they have is M2N, M4N and MN. These have a metallic lustre and are opaque with high conductivity, melting point and are extremely hard. Interstitial Nitrides are inert and prepared by heating the metal in ammonia. One of the characteristics reaction is giving below:

2VN + 3H2SO4 -----> V2(SO4)3 + N2 + 3H2

Covalent Nitrides

Examples are Cyanogen, boron nitride, disulfur dinitride, tetra sulphur tetra nitride and phosphorus nitride. They have a wide range of properties.

Solved Examples

1. What is the Formula for Nitride?

Answer: What is the formula of nitride ion is a very common question. The formula is N-3.

2. What is the Symbol for Nitride?

Answer: Symbol of nitride ion is N-3 while metal Nitrides are of many symbols and notations.

FAQs (Frequently Asked Questions)

1. What are Boron Nitride and its Properties?

Answer: Boron Nitride is isoelectronic with carbon as because both nitrogen and boron together contain the same valence electrons as two carbon atoms bonded together. The two structural forms of boron nitride are similar to graphite and diamond forms of carbon. The hexagonal boron nitride has a layered structure. It can be prepared by heating the trichloride of boron at 750 °C in excess of ammonia. Boron Nitride is a slippery solid, lubricant and completely colourless. It is a good insulator and much more stable than graphite. BN reacts with fluorine to form BF3 and nitrogen. It also reacts with hydrogen fluoride to form NH4BH4. By heating hexagonal BN at 1800°C at high pressure in the presence of alkaline earth metal or alkali metal catalyst, it forms cubic BN.

2. What are the Properties of Cyanogen?

Answer: Cyanogen has a chemical formula of (CN)2. It is a colourless and toxic gas with a boiling point of -21°C. On oxidizing hydrogen cyanide, Cyanogen can be prepared. Oxidizing agents like oxygen gas, nitrogen dioxide gas, chlorine gas can be used. While using NO2, NO is formed as a product. NO can be reused as it again proceeds and reacts to give NO2

2HCN + NO2 -----> (CN)2 + NO + H2O

Polymerization is fostered and facilitated at higher temperatures of 350 to 500 °C by trace impurities in (CN)2. It is converted to a dark solid. It is a six-membered polycyclic structure ring having carbon and nitrogen alternatingly. The molecules of Cyanogen are flammable and linear. It produces an extremely hot flame on burning in oxygen.