What is the oxidation state of chromium in cr2o7^-2
What is the oxidation state of chromium in the dichromate ion, Cr2O7 (2-)
To determine the oxidation state of chromium in the chromate ion (Cr2O7^-2), we need to use the concept of charge balance and the known oxidation states of the other elements in the ion.
First, let's determine the oxidation state of oxygen. Oxygen usually has an oxidation state of -2 in compounds, so the combined oxidation state of the seven oxygen atoms in chromate is -2 * 7 = -14.
The overall charge of the chromate ion is -2. Since the sum of the oxidation states of the atoms in a compound should equal the overall charge, we can set up the following equation:
2x + (-14) = -2
Here, x represents the oxidation state of chromium. The -14 term accounts for the oxidation state of the seven oxygen atoms, each with an oxidation state of -2. The 2x term takes into account the two chromium atoms that are present.
Solving the equation, we have:
2x - 14 = -2
2x = 12
x = 6
So the oxidation state of chromium in the chromate ion is +6.