Stoichiometry (counting in molecules): How many gram-moles of oxygen are present in 6.02 × 10²⁴ molecules of CO? Clarify whether you are counting oxygen as atoms present within CO molecules. Choose the correct value.

Given data & assumption

• 6.02 × 10²⁴ CO molecules contain the same number of oxygen atoms.
• Older phrasing often uses 'gram-molecule' loosely; here we interpret it as moles of oxygen atoms present.

Step-by-StepMoles of CO molecules = (6.02 × 10²⁴)/(6.02 × 10²³) = 10 molEach CO has 1 O atom ⇒ Moles of O atoms = 10 mol

Alternative noteIf the question had asked for O₂ molecules, then 10 mol of O atoms correspond to 5 mol of O₂. But as worded (oxygen present in CO), the count refers to oxygen atoms = 10 mol.

Final Answer10 gram-molecule