Questions: 1. How many moles of acetate ions are present in a sample that contains 4.05 moles of chromium(II) acetate, Cr(CH3COO2) ? moles CH3COO^- 2. How many moles of Cr(CH3COO)2 are present in a sample that contains 3.41 moles of acetate ions? moles Cr(CH3COO)2

Solution Steps

Chromium(II) acetate is represented by the chemical formula \(\mathrm{Cr}\left(\mathrm{CH}_{3} \mathrm{COO}\right)_{2}\). This indicates that each formula unit of chromium(II) acetate contains two acetate ions, \(\mathrm{CH}_{3} \mathrm{COO}^{-}\).

Since each mole of \(\mathrm{Cr}\left(\mathrm{CH}_{3} \mathrm{COO}\right)_{2}\) contains 2 moles of \(\mathrm{CH}_{3} \mathrm{COO}^{-}\), we can calculate the total moles of acetate ions by multiplying the moles of chromium(II) acetate by 2:

\[ \text{Moles of acetate ions} = 4.05 \, \text{moles of } \mathrm{Cr}\left(\mathrm{CH}_{3} \mathrm{COO}\right)_{2} \times 2 = 8.10 \, \text{moles of } \mathrm{CH}_{3} \mathrm{COO}^{-} \]

To find the moles of \(\mathrm{Cr}\left(\mathrm{CH}_{3} \mathrm{COO}\right)_{2}\) from a given number of moles of acetate ions, we divide the moles of acetate ions by 2, since each mole of \(\mathrm{Cr}\left(\mathrm{CH}_{3} \mathrm{COO}\right)_{2}\) contains 2 moles of acetate ions:

\[ \text{Moles of } \mathrm{Cr}\left(\mathrm{CH}_{3} \mathrm{COO}\right)_{2} = \frac{3.41 \, \text{moles of } \mathrm{CH}_{3} \mathrm{COO}^{-}}{2} = 1.705 \, \text{moles of } \mathrm{Cr}\left(\mathrm{CH}_{3} \mathrm{COO}\right)_{2} \]

Final Answer