Final answer:
The oxidation state of chromium (Cr) in zinc dichromate, ZnCr2O7, is +6. This was deduced by setting up an equation considering the known oxidation states of other elements in the compound and solving for Cr.
Step-by-step explanation:
The question asks to determine the oxidation state of chromium (Cr) in the compound zinc dichromate, ZnCr2O7. To find the oxidation state of Cr, we use the general rule that the sum of oxidation states in a neutral compound is zero. Oxygen typically has an oxidation state of -2. Zinc (Zn) has a known oxidation state of +2. Since the compound is composed of one Zn atom, two Cr atoms, and seven oxygen atoms, we can create an equation to solve for the oxidation state of Cr.
The equation will look like this:
- The oxidation state of Zn: +2
- Oxidation state of O: 7(-2) = -14
- Let x be the oxidation state of one Cr atom, therefore for two Cr atoms: 2x
- Overall charge: 0, since the compound is neutral
The sum of all these values must equal zero: +2 + 2x + (-14) = 0. Solving for x yields an oxidation state of +6 for each Cr atom in the compound ZnCr2O7.