Write the empirical formula for at least four ionic compounds that could be formed from the following ions \[ \mathrm{CN}^{-}, \mathrm{NH}_{4}^{+}, \mathrm{Fe}^{3+}, \mathrm{CO}_{3}^{2-} \]

To determine the empirical formulas for ionic compounds, we need to balance the charges of the cations and anions. The empirical formula represents the simplest whole number ratio of the ions in the compound. 1. **Ammonium cyanide (NH4CN):** - Ammonium ion (NH4+) has a charge of +1. - Cyanide ion (CN-) has a charge of -1. - To balance the charges, we need one of each ion. - Empirical formula: NH4CN 2. **Iron(III) cyanide (Fe(CN)3):** - Iron(III) ion (Fe3+) has a charge of +3. - Cyanide ion (CN-) has a charge of -1. - To balance the charges, we need three cyanide ions for every iron(III) ion. - Empirical formula: Fe(CN)3 3. **Ammonium carbonate (NH4)2CO3:** - Ammonium ion (NH4+) has a charge of +1. - Carbonate ion (CO32-) has a charge of -2. - To balance the charges, we need two ammonium ions for every carbonate ion. - Empirical formula: (NH4)2CO3 4. **Iron(III) carbonate (Fe2(CO3)3):** - Iron(III) ion (Fe3+) has a charge of +3. - Carbonate ion (CO32-) has a charge of -2. - To balance the charges, we need three carbonate ions for every two iron(III) ions. - Empirical formula: Fe2(CO3)3 These are the empirical formulas for the four ionic compounds that could be formed from the given ions.