Which of the following has no unpaired electrons but is colo... | CHEMISTRY - SOME IMPORTANT COMPOUNDS OF TRANSITION ELEMENTS | SolveeIt

Which of the following has no unpaired electrons but is coloured?

$K_{2}Cr_{2}O_{7}$

$K_{2}MnO_{4}$

$CuSO_{4}.5H_{2}O$

$MnCl_{2}$

Answer

$K_{2}Cr_{2}O_{7}$

Explanation

In $K_{2}Cr_{2}O_{7},$ the oxidation number of Cr = +6

The electronic configuration of $Cr^{6 +}$ is

$24C^{6 +} \rightarrow \lbrack Ar\rbrack 3d^{0}4s^{0}$

So it has no unpaired electron but is orange coloured.

Question: Which of the following has no unpaired electrons but is coloured?...