As the name suggests, hydrides are compounds that are hydrogen-bonded with other elements. Hydrides are anions of the hydrogen atom. Hydrogen is highly reactive with all the elements of the periodic table. That is the reason hydrides can be formed with all the elements of the periodic table except noble gases. The only difference between compounds of hydrogen and hydrides is: Hydrides have less electronegativity..
According to the formation of the hydrides and the chemical bonding present in them, hydrides can be divided into three major types: Ionic or saline hydrides, metallic hydrides, and covalent hydrides.
Hydrides: Basics
Hydrides can be defined as any element or compound that combines with hydrogen atoms to form a definitive compound. Hydrides can be used in generic as well as in specific terms. Initially, any compound atom and a covalent bond were known as a hydride. However, hydrides are ions or molecules that have the hydrogen atom bonded to them with a covalent bond. It is always bonded to a less electronegative element. The core of the hydrogen has a nucleophilic property.
Due to the high reactivity of hydrogen, it bonds with all the elements of the periodic table whether they are slightly or extremely covalent. There are many exceptions as well. For instance, the hydride importance can be seen in the exception of boron hydrides where their bonding is explained by a multi-centered bond. Hydride can consist of single molecules, double molecules, or numerous molecules. That is how they are classified into polymers, bulk metals, oligomers, or ionic solids.
Types of Hydrides in Chemistry
Hydrides are complex compounds that are divided into three types based on the type of chemical bonds present between the elements. The basic type of hydrides are:
- Ionic or saline hydrides
- Covalent hydrides
- Metallic hydrides
Ionic or Saline hydrides
These hydrides are formed with the hydrogen atom reacting with alkali metals or alkaline earth metals. They are highly electropositive. They form the major part of the s-block elements. These hydrides do not dissolve in basic solvents. That is why they are used as bases. The bond is always formed with more electropositive elements of the periodic table. These compounds are binary compounds.
The main examples of ionic hydrides are NaH, KH, and so on. All these hydrides have hydrogen as an anion.
Metallic Hydrides
In this type of hydride, the hydrogen atom forms a bond with the metal. This is the reason it is known as a metallic hydride. The bond form here is mostly covalent. However, the bond formed between the metal and hydrogen can be ionic too. They are transition metals. They have high melting and boiling questions.
The other name for metal hydrides is interstitial hydrides. These are formed when the hydrogen atom reacts with the elements of the D-block and F-block.
Covalent Hydrides
These hydrides are formed when we see the hydrogen atom react with electronegative elements like carbon, silicon, nitrogen, and so on. Generally, These compounds are nonmetallic. They are volatile or non-volatile.
These hydrides are either gases or liquids. The main examples are SiH4, NH3, and CH4.
What are the various uses of hydrides?
Due to the varied nature of hydrides, it finds several uses in chemistry as well as in real life. There are many uses of hydrides that help us understand hydrides better. The various uses of hydrides are mentioned below:
- Hydrides like Sodium hydride (NaH) and Potassium hydride (KH) are strong bases. That is why they are used in organic synthesis. When they combine with a bronsted acid, they liberate hydrogen gas.
- Hydrides play an important role in the battery technology industry. They are used as hydrogen storage that can be easily carried anywhere. This hydrogen is used for powering electric vehicles.
- Hydrides are used as drying agents that help in traces of water from organic solvents.
- Hydrides can also be used as reducing agents. It mostly takes place in chemical synthesis.
- They can also be used as catalysts for many catalytic cycles. The various catalytic cycles are hydrogenation, hydroformylation, and hydrosilylation.
- Ionic hydrides are excellent fuels because they liberate dihydrogen when heated. They also produce light.
- Sodium borohydride easily dissolves in common solvents and thus, it is used in the synthesis of organic compounds.
- Metallic hydrides can absorb hydrogen very quickly on the surface.
Conclusion
In this module, we discussed the various aspects of hydrides. A hydride has a hydrogen atom in its compound. The hydride is the negative ion or anion of the hydrogen atom. Hydrides are anions for the negatively charged part of the hydrogen atom. Hydrogen is highly reactive with all the elements of the periodic table. Hydride can consist of single molecules, double molecules, or numerous molecules. There are three types of hydrides as well: ionic or saline hydrides, covalent hydrides, and metallic hydrides. Hydrides also find many uses in real life. The various uses of hydrides include: hydrides are used as reducing agents, they are used in the synthesis of organic compounds, they are used as reducing agents too, and so on. Sodium borohydride easily dissolves in common solvents and thus, it is used in the synthesis of organic compounds. We also discussed the various hydrides