Question

The composition of mischmetal is:
A.\[5\% \] of a lanthanoid metal, \[95\% \] of iron and traces of a \[{\text{S , C , Ca and Al}}\]
B.\[95\% \] of a actinide metal, \[5\% \] of iron and traces of a \[{\text{S , C , Ca and Al}}\]
C.\[95\% \] of a lanthanoid metal, \[5\% \] of iron and traces of a \[{\text{S , C , Ca and Al}}\]
D.\[95\% \] of a transition metal, \[5\% \] of iron and traces of a \[{\text{S , C , Ca and Al}}\]

Answer 1

Hint: The mischmetal contains a mixture of lanthanide elements along with some rare earth elements. The percentage of lanthanides is very high in mischmetal.

Complete step by step answer:
The word mischmetal is derived from the German name that means mixed metal. It is an alloy. The other names of mischmetal are cerium mischmetal and rare earth mischmetal. Mischmetal is called rare earth mischmetal because it is made up of rare Earth elements and obviously it is called cerium metal because of the presence of the lanthanoid element that is cerium.
General composition of mischmetal includes \[55\% \] cerium, \[25\% \] lanthanum, 15% neodymium and other rare metals. In some form it even contains 95% lanthanoid and 5% iron.

Hence, the correct option is C.

Note:
Mischmetal is also used to prepare the rare Earth elements. As their composition is less in Earth crust. So, the normal processes are not capable enough to distinguish them. Highly specialized processes are used to produce rare earth metal from Mischmetal.
Note: Mischmetal is most commonly used in lighters and torch in ignition. So rare earth element composition is Mischmetal is soft enough to be used in torches and lights. That is why it is mixed with iron oxide or magnesium oxide to make it a harder material known as ferrocerium.