Final answer:
To find the number of O₂ molecules needed, the mass of sulfur is first converted to moles and then compared to the stoichiometry of the reaction with O₂, showing that 0.232 moles of O₂ are needed, which doesn't match the provided options.
Step-by-step explanation:
To determine how many O₂ molecules are needed to react with 7.44 g of sulfur (S), first we need to find out how many moles of S we have. The molar mass of sulfur (S) is approximately 32.07 g/mol. So, we divide the given mass of sulfur by its molar mass to get the number of moles:
7.44 g S ÷ 32.07 g/mol = 0.232 mol S
Sulfur reacts with oxygen according to the reaction: S(s) + O₂(g) → SO₂(g). From this stoichiometric equation, we see that 1 mole of S reacts with 1 mole of O₂. Thus, for 0.232 moles of S, we need 0.232 moles of O₂, which is less than any of the answer choices provided. Therefore, the question may have a typo or may be incorrectly stated as none of the answer choices (A to D) are correct based on the given mass of sulfur.