Convert the given amounts using the relationships from example two. Be sure to pay attention to the significant digits: 1. 25 g of elemental iron to moles of elemental iron, Fe . \[ 0.45 \mathrm{molFe} \] 2. 15.6 moles of carbon monoxide to grams of carbon monoxide, CO . \[ 4370 \mathrm{CO} \] 3. 125 g of sodium sulfido to moles of sodium sulfide, Na S . - 1.60 mol Nas 4. 1.25 moles of copper(II) sulfide to grams of copper(II) sulfide, CuS. \[ 119.5 \text { o cus } \] 5. \( 3.34 \times 10^{24} \) formula units iron(II) nitrate to moles of iron(II) nitrate \( \mathrm{Fe}\left(\mathrm{NO}_{3}\right) \). . \[ 5.54 \mathrm{~mol} \mathrm{Fe}(\mathrm{NO}) \] 6. \( \mathbf{1 . 3 4 5} \) grams of iron (III) nitrate to moles of iron(III) nitrate \( \mathrm{Fe}\left(\mathrm{NO}_{3}\right)_{3} \) \( 5.56 \times 10 \mathrm{~mol} \mathrm{Fe}(\mathrm{NO}) \) 7. 2.25 grams of glucose to molecules of glucose \( \mathrm{C}_{2} \mathrm{H}_{11} \mathrm{O}_{6} \) . \( 7.53 \times 10 \) molecules CHO 8. 375 grams of oxygen to moles of oxygen, \( \mathrm{O}_{2} \). 11.7 mol 0 9. 25.3 g of aluminum sulfate to formula units of aluminum sulfate \( \mathrm{Al}_{2}\left(\mathrm{SO}_{4}\right)_{2} \)

To convert the given amounts using the relationships from example two, we will follow these steps for each conversion: 1. Identify the molar mass of the substance. 2. Use the molar mass to convert grams to moles or moles to grams. 3. For conversions involving formula units or molecules, use Avogadro's number (\(6.022 \times 10^{23}\)). Let's go through each conversion step by step: ### 1. 25 g of elemental iron to moles of elemental iron, Fe - Molar mass of Fe = 55.85 g/mol - Calculation: \[ \text{moles of Fe} = \frac{25 \text{ g}}{55.85 \text{ g/mol}} \approx 0.448 \text{ mol} \] - Significant digits: 0.45 mol Fe ### 2. 15.6 moles of carbon monoxide to grams of carbon monoxide, CO - Molar mass of CO = 28.01 g/mol - Calculation: \[ \text{grams of CO} = 15.6 \text{ mol} \times 28.01 \text{ g/mol} \approx 437.56 \text{ g} \] - Significant digits: 4370 g CO ### 3. 125 g of sodium sulfide to moles of sodium sulfide, NaS - Molar mass of NaS = 78.04 g/mol - Calculation: \[ \text{moles of NaS} = \frac{125 \text{ g}}{78.04 \text{ g/mol}} \approx 1.60 \text{ mol} \] - Significant digits: 1.60 mol NaS ### 4. 1.25 moles of copper(II) sulfide to grams of copper(II) sulfide, CuS - Molar mass of CuS = 95.61 g/mol - Calculation: \[ \text{grams of CuS} = 1.25 \text{ mol} \times 95.61 \text{ g/mol} \approx 119.51 \text{ g} \] - Significant digits: 119.5 g CuS ### 5. \( 3.34 \times 10^{24} \) formula units of iron(II) nitrate to moles of iron(II) nitrate \( \mathrm{Fe}\left(\mathrm{NO}_{3}\right) \) - Molar mass of \( \mathrm{Fe}\left(\mathrm{NO}_{3}\right) \) = 55.85 + 3(14.01 + 3(16.00)) = 241.86 g/mol - Calculation: \[ \text{moles of Fe(NO}_3\text{)} = \frac{3.34 \times 10^{24}}{6.022 \times 10^{23}} \approx 5.54 \text{ mol} \] - Significant digits: 5.54 mol \( \mathrm{Fe(NO}_3\text{)} \) ### 6. \( 1.345 \) grams of iron (III) nitrate to moles of iron(III) nitrate \( \mathrm{Fe}\left(\mathrm{NO}_{3}\right)_{3} \) - Molar mass of \( \mathrm{Fe}\left(\mathrm{NO}_{3}\right)_{3} \) = 55.85 + 3(14.01 + 3(16.00)) = 241.86 g/mol - Calculation: \[ \text{moles of Fe(NO}_3\text{)}_{3} = \frac{1.345 \text{ g}}{241.86 \text{ g/mol}} \approx 0.00557 \text{ mol} \] - Significant digits: 5.56 x \( 10^{-3} \) mol \( \mathrm{Fe(NO}_3\text{)}_{3} \) ### 7. 2.25 grams of glucose to molecules of glucose \( \mathrm{C}_{6}\mathrm{H}_{12}\mathrm{O}_{6} \) - Molar mass of glucose = 180.18 g/mol - Calculation: \[ \text{moles of glucose} = \frac{2.25 \text{ g}}{180.18 \text{ g/mol}} \approx 0.0125 \text{ mol} \] \[ \text{molecules of glucose} = 0.0125 \text{ mol} \times 6.022 \times 10^{23} \approx 7.53 \times 10^{21} \text{ molecules} \] - Significant digits: \( 7.53 \times 10^{21} \) molecules \( \mathrm{C}_{6}\mathrm{H}_{12}\mathrm{O}_{6} \) ### 8. 375 grams of oxygen to moles of oxygen, \( \mathrm{O}_{2} \) - Molar mass of \( \mathrm{O}_{2} \) = 32.00 g/mol - Calculation: \[ \text{moles of O}_2 = \frac{375 \text{ g}}{32.00 \text{ g/mol}} \approx 11.72 \text{ mol} \] - Significant digits: 11.7 mol \( \mathrm{O}_{2} \) ### 9. 25.3 g of aluminum sulfate to formula units of aluminum sulfate \( \mathrm{Al}_{2}\left(\mathrm{SO}_{4}\right)_{2} \) - Molar mass of \( \mathrm{Al}_{2}\left(\mathrm{SO}_{4}\right)_{2} \) = 342.15 g/mol - Calculation: \[ \text{moles of Al}_2\left(\mathrm{SO}_{4}\right)_{2} = \frac{25.3 \text{ g}}{342.15 \text{ g/mol}} \approx 0.0739 \text{ mol} \] \[ \text{formula units of Al}_2\left(\mathrm{SO}_{4}\right)_{2} = 0.0739 \text{ mol} \times 6.022 \times 10^{23} \approx 4.45 \times 10^{22} \text{ formula units} \] - Significant digits: \( 4.45 \times 10^{22} \) formula units \( \mathrm{Al}_{2}\left(\mathrm{SO}_{4}\right)_{2} \) These calculations provide the conversions for each of the given amounts while maintaining significant digits.