Question

An ion $M^{2+}$, forms the complexes ${\left[M{\left(H_{2}O\right)}_6\right]}^{2+},{\left[M{\left(en\right)}_3\right]}^{2+}$ and ${\left[{MBr}_6\right]}^{4-}$. The colour of the complexes will be _____________ respectively.

• A. green, blue and red
• B. blue, red and green
• C. green, red and blue
• D. red, blue and green

Answer 1

The correct option is B blue, red and green

Crystal Field Stabilization Energy(CFSE) is proportional to the frequency of the absorbed light. The emitted colors are red, green and blue. The corresponding absorbed colors are green, red and orange. So the first complex will be blue, second is red and third is green.