Which one amongst the following are good oxidising agents? (a) Sm 2 + (b) Ce 2 + (c) Ce 4 + (d) Tb 4 + Choose the most appropriate answer from the options given below :

Step-by-step solution

The common oxidation state of lanthanide is + 3 . The lanthanide ions having + 2 oxidation state undergo oxidation readily, hence they act as reducing agents. The lanthanide ions having + 4 oxidation state undergo reduction readily, hence they act as oxidising agents. Hence, Ce + 4 and Tb + 4 act as oxidising agent