Hydride is an anion of hydrogen, and is a chemical compound in which hydrogen atoms possess nucleophilic, basic or reducing properties, and have an oxidation number of -1. Examples of hydride compounds include water (H2O), methane (CH4) and ammonia (NH3).

Table of Contents

Hydrides

Types of Hydrides

Covalent Hydrides

Uses of Hydride

Hydrides are compounds formed by the combination of hydrogen and another element or group of elements. They are usually covalently bonded and have a negative charge.

Compounds of hydrogen with less electronegative elements are known as hydrides. When hydrogen reacts with any other element, the product formed is also a hydride. The hydride gap is the condition where VA group elements in the periodic table do not form hydrides. Hydrogen molecules usually react with many elements, except noble gases, to form hydrides. However, the properties of the hydride may vary depending on the type of intermolecular force between the elements, its molecular mass, temperature, and other factors.

Types of Hydrides

Hydrides are mainly divided into three major types or groups, which are based on the chemical bonding of the elements the hydrogen forms bonds with. These three types of hydrides are ionic, covalent, and metallic hydrides, and we will learn more about them in detail below.

Ionic or Saline Hydrides

Ionic hydrides are formed when hydrogen molecules react with highly electropositive s-block elements (Alkali Metals and Alkaline Earth Metals). In solid-state, they are crystalline, non-conducting and non-volatile, but in liquid state, they are able to conduct electricity. Upon electrolysis, these ionic hydrides release hydrogen gas at the anode. Saline or ionic hydrides do not dissolve in conventional solvents and are typically used as bases or reducing reagents in organic synthesis.

Example of Ionic Hydrides: Nah, KH, CaH₂, etc. These contain hydrogen as the negatively charged (H^-) ion.

⇒ Also Read:

Alkali Metals

Alkaline Earth Metals

Covalent Hydrides

Covalent hydrides are formed when hydrogen reacts with other electronegative elements such as silicon, carbon, etc. Common examples include methane (CH₄) and ammonia (NH₃). In general, compounds that result from the reaction between hydrogen and non-metals are referred to as covalent hydrides. These compounds share covalent bonds and can be either volatile or non-volatile. Covalent hydrides can also exist as either liquids or gases.

Answer: Examples of Covalent Hydrides:

• SiH4 (silane)

Metallic Hydrides

A metal hydride is a hydrogen compound that forms a bond with another metal element. The bond is usually of a covalent type, but sometimes hydrides are formed with ionic bonds, usually between transition metals. These hydrides are usually non-stoichiometric, hard, with high melting and boiling points.

Examples of Metallic Hydrides:

• TiH
• Aluminium
• Cadmium
• Magnesium
• etc.

Metal hydrides, also known as interstitial hydrides, are formed when hydrogen molecules react with d- and f-block elements. Metals from groups 7, 8, and 9, however, do not form hydrides. Although they do conduct heat and electricity, it is not to the same degree as their parent metals.

Uses of Hydride

Hydride compounds are used in a variety of applications, including fuel cells, metal hydrides, hydrogen storage, and hydrogenation reactions.

They are used as reducing agents in numerous chemical industries.

Hydrides are of great importance in battery storage technologies, such as nickel hydride batteries.

They are used as drying agents.

They are often used as strong bases in organic synthesis.

Metal hydrides are also used for their capacity to store heat, store hydrogen, and act as compressors.

Frequently Asked Questions (FAQs)

The formula of hydride is H₂.

Hydrides are classified according to the type of elements they contain, such as covalent hydrides, ionic hydrides, and interstitial hydrides.

When an ionic hydride reacts with water, it typically forms an acidic solution due to the dissociation of the hydrogen ions.

No, NaH is not electron deficient.

Electron rich hydrides are hydrides that contain more electrons than protons, resulting in a negative oxidation state. Examples of electron rich hydrides include NaH, LiH, and CaH2.

Electron-rich hydrides are hydrides which have excess electrons to form bonds. For example, NH3 is an electron-rich hydride.