What is the Difference Between Ionic Covalent and Metallic Hydrides?

The main difference between ionic, covalent, and metallic hydrides lies in the type of chemical bond involved and the elements they are formed with. Here is a summary of the three types of hydrides:

1. Ionic Hydrides:

• Formed when hydrogen reacts with highly electropositive s-block elements (alkali metals and alkaline earth metals).
• Generally binary compounds, insoluble in solutions.
• In the solid state, they are crystalline, non-conducting, and non-volatile, but in the liquid state, they conduct electricity.
• Examples: NaH, CaH2.

1. Covalent Hydrides:

• Formed when hydrogen reacts with non-metals, sharing a covalent bond.
• Can be volatile or non-volatile compounds, either liquids or gases.
• Examples: SiH4 (silane).

1. Metallic Hydrides:

• Formed when hydrogen reacts with transition metals or their alloys.
• Also known as interstitial hydrides.
• The bond is mostly covalent, but sometimes hydrides are formed with ionic bonds.
• They conduct heat and electricity, but not to the extent of their parent metals.
• Examples: TiH, aluminium, cadmium, magnesium.

In summary, ionic hydrides are formed with highly electropositive elements, covalent hydrides are formed with non-metals, and metallic hydrides are formed with transition metals. The physical properties and chemical bonding of these hydrides depend on the type of hydride and the elements involved.

Comparative Table: Ionic Covalent vs Metallic Hydrides

Here is a table comparing the differences between ionic, covalent, and metallic hydrides:

Ionic hydrides are formed when hydrogen reacts with highly electropositive s-block elements, resulting in ionic bonds. In contrast, covalent hydrides form when hydrogen reacts with non-metals, sharing covalent bonds. Metallic hydrides, on the other hand, are formed when hydrogen reacts with transition metals, mostly through covalent bonds, but sometimes through ionic bonds.