Question

Write two uses of lanthanoids.

Mention some of the important uses of lanthanoids.

Discuss the important uses of lanthanoids.

Answer 1

1. It is used in a colour television tube.
2. It is used in optical fibres.
3. It is used in hybrid cars, superconductors, and permanent magnets. 

Answer 2

Lanthanoids are not very useful when they are pure. But in the form of their compounds and alloys, they are quite helpful. Some examples are as follows:

1. Misch metals containing 30-35% of Ce, along with smaller quantities of other light lanthanoids, are used as reducing agents in metallurgical operations.
2. Mg-alloys containing about 30% misch metal and 1% Zr are used for making parts of a jet engine.
3. Pyrophoric alloys containing rare earth metals are used in the preparation of ignition devices such as tracer bullets, shells, and flints for lighters.
4. Cerium salts are used in medicine, cotton dyeing, and qualitative and quantitative analysis.
5. Cerium phosphate is used as a catalyst in the petroleum industry.
6. Glass is coloured, and optical filters can be made using Nd₂O₄ and Pr₂O₃.