What is the mass of 3.35 moles SO3 *

268 grams

Explanation:

Number of moles of SO3 = 3.35 moles

Molar mass of SO3 = (32 + (16 x 3)

= 32 + 48 = 80g/mole

(Molar mass was calculated using the mass number of Sulphur: 32, and oxygen: 16)

Now, recall that:

Number of moles = (mass/molar mass)

3.35 moles = Mass / 80g/mole

Mass = 3.35 moles x 80g/mole

Mass = 268 grams

Thus, the mass of 3.35 moles of SO3 is 268 grams