Final answer:
To calculate the mass of 3.65 x 10²⁰ molecules of sulfur trioxide (SO₃), multiply the given number of molecules by the molar mass of SO₃ (80.06 g/mol). The mass is 2.92 x 10²² g.
Step-by-step explanation:
To calculate the mass of 3.65 x 10²⁰ molecules of sulfur trioxide (SO₃), we need to use the molar mass of SO₃. The molar mass of SO₃ is 80.06 g/mol. We can use the following conversion factor:
1 mol SO₃ = 80.06 g SO₃
To calculate the mass, we can multiply the given number of molecules by the molar mass:
Mass = (3.65 x 10²⁰ molecules) * (80.06 g/mol)
Mass = 2.92 x 10²² g