Vitamin B12 contains
- Fe(II)
- Co(III)
- Zn(II)
- Ca(II)
Answer
(2) Co(III)
Solution
As per NCERT, vitamin B12, cyanocobalamine, the anti-pernicious anaemia factor, is a coordination compound of cobalt.
Cobalt is present in the +3 oxidation state, Co(III), at the centre of the corrin ring.
Answer: (2)