How many O2 molecules are needed to react with 6.16g of S?
To find the number of O2 molecules needed to react with 6.16g of S, we first need to determine the molar mass of sulfur (S). The molar mass of S is approximately 32.07 g/mol.
Next, we need to calculate the number of moles of S in 6.16g. This can be done by dividing the given mass by the molar mass of S:
Number of moles of S = 6.16g / 32.07 g/mol ≈ 0.192 mol
Since the balanced chemical equation for the reaction is:
2S + 3O2 -> 2SO3
We can see that 2 moles of O2 react with 2 moles of S. This means that the ratio of moles of O2 to S in the reaction is 3:2.
Therefore, the number of moles of O2 needed to react with 0.192 moles of S can be calculated as follows:
Number of moles of O2 = (3/2) x 0.192 mol ≈ 0.288 mol
Finally, we can convert the number of moles of O2 to number of molecules using Avogadro's number (6.022 x 10^23 molecules/mol):
Number of molecules of O2 = 0.288 mol x 6.022 x 10^23 molecules/mol ≈ 1.73 x 10^23 molecules
Therefore, approximately 1.73 x 10^23 molecules of O2 are needed to react with 6.16g of S.