Explain in detail how to determine the chemical formula for Chromium (II) iodate.
The correct answer and explanation is:
To determine the chemical formula for Chromium (II) iodate, you need to consider both the oxidation states of the elements involved and the charge balance between the ions.
- Identify the ions:
- Chromium (II) refers to chromium in the +2 oxidation state. This means the chromium ion is Cr²⁺.
- Iodate is a polyatomic ion with the formula IO₃⁻. This ion consists of iodine (I) in the +5 oxidation state, with three oxygen atoms, each of which has a -2 charge. The overall charge of the iodate ion is -1.
- Determine the ratio of ions:
- Since the chromium ion has a charge of +2 (Cr²⁺) and the iodate ion has a charge of -1 (IO₃⁻), you need to balance the charges. To achieve charge neutrality, you need two iodate ions to balance the +2 charge from one chromium ion. This results in a formula of Cr(IO₃)₂.
- Write the formula:
- The chemical formula is written by placing the chromium ion (Cr²⁺) followed by the iodate ion (IO₃⁻) with the appropriate subscript to indicate the correct ratio. Since two iodate ions are needed to balance one chromium ion, the formula is Cr(IO₃)₂.
- Check for consistency:
- The charges must balance out. In this case, Cr²⁺ contributes +2, and two iodate ions, each with a charge of -1, contribute -2. The charges cancel out, confirming that the formula Cr(IO₃)₂ is correct.
So, the correct chemical formula for Chromium (II) iodate is Cr(IO₃)₂.