Answer :
The mass of SF6 in a 15.0 L tank at STP can be found by first calculating the number of moles (Volume / Molar volume) and then multiplying by the molar mass of SF6. The correct answer is (c) 97.7 g.
To calculate the mass of SF6 (sulfur hexafluoride) in a 15.0-L tank at STP (standard temperature and pressure), we use the concept of molar volume. At STP, one mole of any gas occupies 22.4 liters. Therefore, we can determine the number of moles of SF6 by dividing the volume of the gas (15.0 L) by the molar volume (22.4 L/mol):
Number of moles = Volume of gas / Molar volume = 15.0 L / 22.4 L/mol
After calculating the number of moles, we can find the mass by multiplying the number of moles by the molar mass of SF6 (146.06 g/mol):
Mass = Number of moles
Mass = (15.0 L / 22.4 L/mol)
The correct answer for the mass of SF6 in the tank at STP is (c) 97.7 g, calculated by the number of moles times the molar mass of SF6.