Question

In Cr(CO)6, when solving the Oxidation Number of Cr, why do we take oxidation number of CO to be 0?

Answer 1

Answer:

In CrO  5

​

, one oxygen is attached to Cr through the double bond. It has oxidation number −2. Four oxygen atoms are attached to Cr atom through a single bond. Each of these oxygen has an oxidation number −1.

Let x be the oxidation number of chromium. The sum of all the oxidation numbers is zero.  

Hence, x−2+4(−1)=0 and x=6.  

Thus, the oxidation number of chromium in CrO  5   is +6.  

The structure of CrO  5

​

Explanation:

The net charge on neutral atoms or molecules is zero. So the overall oxidation state of them is zero.

Answer 2

Answer:

he charge on the complex and of the neutral ligänd is zero. Thus, making the chromium metal a zerovalent, that is, the oxïdation state is zero and has the IUPAC name as Hexacarbonyl chromium (0). So, the oxïdation state of the chrōmium in Cr(CO)6 is option (A)- 0.