Match the compounds/elements given in Column I with uses given in Column II.

Column II
A. Lanthanoid oxide 1. Petroleum cracking
B.  Lanthanoid 2.  Television screen
C. Mischmetal 3. Lanthanoid metal + iron
D. Mixed oxides of lanthanoids are
4. Production of iron alloy


Options: A B C D
1. 2 1 4 3
2. 1 2 3 4
3. 2 4 3 1
4. 4 1 3 2


Hint: Mischmetall which consists of a lanthanoid metal(~ 95%) and iron (~ 5%) and traces of S, C, Ca and Al.
The compounds and its use are as follows:

        Compound / Element


A. Lanthanoid oxide

Television screen

B. Lanthanoid

Production of iron alloy

C. Mischmetall

Lanthanoid metal + iron

D. Mixed oxides of lanthanoids are employed

Petroleum cracking

Yttrium, europium, and terbium phosphors are the red-green-blue phosphors used in many light bulbs, panels, and televisions.

Lanthanum-based catalysts are used to refine petroleum. Cerium(IV) oxide(CeO2) is finding use as a petroleum cracking catalyst in petroleum refining.

Hence, option third is the correct answer.