Types of hydrides

The hydrides include ionic hydrides, molecular hydrides and metal hydrides
.

1.
Ionic hydride

Hydrogen directly combines with alkali metals and most alkaline earth metals at higher temperatures to form ionic hydrides
.

Alkali metal and alkaline earth metal hydrides are white or off-white, and many of their properties are similar to salts, so they are sometimes called salt hydrides
.

The ionic hydride reacts violently with water and releases hydrogen
.

NaH+H ₂ O=H ₂ +NaOH

In non-aqueous polar solvents, ionic hydrides can combine with some electron-deficient compounds to form complex hydrides
.

Both ionic hydride and composite hydride have strong reducing properties and are good reducing agents
.

TiCl ₄ +4NaH=Ti+4NaCl+2H ₂

2.

The hydrides of the elements in the p-zone of the periodic table belong to molecular crystals.
This type of hydride has a low boiling point and melts.
Under normal conditions, it is mostly a gas, so it is called a molecular hydride
.

The properties of molecular hydrides in water vary greatly
.

3.

The hydrides of d-block elements and f-block elements basically retain the metal-specific physical properties such as metallic luster and conductivity, so they are called metallic hydrides
.

Some metal hydrides are full-scale compounds, such as CrH ₂ , NiH, CuH, and ZnH ₂ ; others are non-scale compounds, such as PdH0.

Pt cannot form hydrides, but hydrogen can form chemical adsorption on the surface of Pt, and Pt can be used as a catalyst in the hydrogenation reaction

Related Links: Properties and Preparation of Hydrogen