MCQ
The vitamin having metal atom is?
- AVitamin $A$
- BVitamin $K$
- ✓Vitamin $\mathrm{B}_{12}$
- DVitamin $C$
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Assertion $A$: Permanganate titrations are not performed in presence of hydrochloric acid.
Reason $R$ : Chlorine is formed as a consequence of oxidation of hydrochloric acid.
In the light of the above statements, choose the correct answer from the options given below.
Assume Planck's constant $( h )=6.4 \times 10^{-34}\,Js$ Speed of light $( c )=3.0 \times 10^8\,m / s$ and Avogadro's constant $\left( N _{ A }\right)=6 \times 10^{23} / mol$