How many molecules are in 3.94g of SO2?

To find the number of molecules, you need to first convert the mass into number of mol using the molar mass of SO2, simply add the atomic masses of each element and the number of times each element appears in the formula from the periodic table.

Then divide the mass by that value and then use Avogadro’s number to find the molecules.

Multiply by 6.02 x 10^23 Molecules.