Question

The solid anhydrous solid CoCl2 is blue in color. Because it readily absorbs water from the air, it is used as a humidity indicator to monitor if equipment (such as a cell phone) has been exposed to excessive levels of moisture. Predict what product is formed by this reaction, and how many unpaired electrons this complex will have.

Answer 1

Answer:

$CoCl_{2}.(H_{2}O)_{6}$ is formed and it has three unpaired electrons.

Explanation:

Blue $CoCl_{2}$ reacts with water to produce pink colored $CoCl_{2}.(H_{2}O)_{6}$ complex.

In this complex, $Co^{2+}$ ion forms an octahedral complex with six $H_{2}O$ ligands.

As $H_{2}O$ is a weak field ligand therefore $Co^{2+}$ ion remains in low spin state.

Hence electronic configuration of $Co^{2+}$ ion in this octahedral geometry is $t_{2g}^{5}e_{g}^{2}$ with total three unpaired electrons.