The oxidation of chromium in Cr\(_2\)O\(_7)\(-2\) ?

The oxidation state of chromium in the Cr\(_2\)O\(_7)\(-2\) ion is +6. The oxidation state of an element refers to the number of electrons it has lost or gained in a chemical reaction. In the Cr\(_2\)O\(_7)\(-2\) ion, there are two chromium atoms, each with a different oxidation state. To determine the oxidation state of chromium in the Cr\(_2\)O\(_7)\(-2\) ion, we need to consider the overall charge of the ion, which is -2. Oxygen has an oxidation state of -2, so the seven oxygen atoms in the ion contribute a total oxidation state of -14. We also know that the oxidation state of the entire Cr\(_2\)O\(_7)\(-2\) ion is -2, so the two chromium atoms must contribute a total oxidation state of +12 to balance out the negative charge. Since there are two chromium atoms, each chromium atom must have an oxidation state of +6. This is because +6 + +6 = +12, which balances out the -2 charge on the ion. Therefore, the oxidation state of chromium in the Cr\(_2\)O\(_7)\(-2\) ion is +6.