Questions: How many moles of sulfate ions are contained in 250 grams of aluminum sulfate? There are 0.731 moles of sulfate ions in 250 grams of aluminum sulfate There are 2.19 moles of sulfate ions in 250 grams of aluminum sulfate. There are 1.46 moles of sulfate ions in 250 grams of aluminum sulfate. There are 2.92 moles of sulfate ions in 250 grams of aluminum sulfate.

Solution Steps

The chemical formula for aluminum sulfate is \( \text{Al}_2(\text{SO}_4)_3 \).

To find the molar mass, we sum the atomic masses of all atoms in the formula:

• Aluminum (Al): \( 2 \times 26.98 \, \text{g/mol} = 53.96 \, \text{g/mol} \)
• Sulfur (S): \( 3 \times 32.07 \, \text{g/mol} = 96.21 \, \text{g/mol} \)
• Oxygen (O): \( 12 \times 16.00 \, \text{g/mol} = 192.00 \, \text{g/mol} \)

Total molar mass of \( \text{Al}_2(\text{SO}_4)_3 \): \[ 53.96 + 96.21 + 192.00 = 342.17 \, \text{g/mol} \]

Using the molar mass, we can find the number of moles of aluminum sulfate in 250 grams: \[ \text{moles of } \text{Al}_2(\text{SO}_4)_3 = \frac{250 \, \text{g}}{342.17 \, \text{g/mol}} = 0.7305 \, \text{moles} \]

Each formula unit of aluminum sulfate contains 3 sulfate ions (\(\text{SO}_4^{2-}\)).

Therefore, the moles of sulfate ions are: \[ \text{moles of } \text{SO}_4^{2-} = 0.7305 \, \text{moles of } \text{Al}_2(\text{SO}_4)_3 \times 3 = 2.1915 \, \text{moles} \]

Final Answer