Final answer:
The mass of sulfur hexafluoride, SF6, that has the same number of fluorine atoms as 25.0 g of oxygen difluoride, OF2, is found to be 8.691 g by calculating the moles of fluorine in OF2 and equating it to moles in SF6.
Step-by-step explanation:
To determine the mass of sulfur hexafluoride, SF6, that contains the same number of fluorine atoms as 25.0 g of oxygen difluoride, OF2, we use the concept of moles and Avogadro's number. First, we calculate the number of moles of OF2 in 25.0 g by using its molar mass (OF2: 32.00 g/mol for O + 2(19.00 g/mol) for F = 70.00 g/mol). With this, we have:
25.0 g OF2 × (1 mol OF2/70.00 g) = 0.357 moles of OF2
Since OF2 contains two fluorine atoms, 0.357 moles of OF2 will contain 2 × 0.357 moles of fluorine atoms. Each SF6 molecule contains six fluorine atoms, therefore:
0.357 moles of F atoms × (1 mol SF6/6 mol F atoms) = 0.0595 moles of SF6
Finally, we calculate the mass using the molar mass of SF6 (146.06 g/mol):
0.0595 moles SF6 × 146.06 g/mol = 8.691 g of SF6
Therefore, 8.691 g of SF6 contains the same number of fluorine atoms as 25.0 g of oxygen difluoride, OF2.