Answer :
- The mass of SF₆ in a 15.0 L tank at STP can be calculated to be 97.7 g.
- Option 'c' is the correct answer.
1. Given molar mass of SF₆ = 146.06 g/mol and volume of tank = 15.0 L.
2. At STP (Standard Temperature and Pressure), 1 mole of any gas occupies 22.4 L.
3. Calculate the number of moles of SF₆ in the tank using the ideal gas law: n = PV / RT, where P = 1 atm, V = 15.0 L, R = 0.0821 L.atm/mol.K, and T = 273 K.
4. Once you have the number of moles, use the molar mass to find the mass of SF₆ in grams.
5. Mass = Number of moles * Molar mass.
6. Substituting the values, you will find the mass of SF₆ in the tank to be 97.7 g.
The correct answer is option [C].