Given: Molecular formula of the compound is C₈H₁₁O₂
Since C₈H₁₁O₂ molecule contains two atoms of oxygen which is equal to one mole.
∵ In 1 mole of C₈H₁₁O₂, oxygen has = 1.0 mole
∴ In 3.7 moles of C₈H₁₁O₂, oxygen has = (1.0 mole) × (3.7 moles) ÷ (1 mole)
= 3.7 moles
Hence, oxygen has 3.7 moles in 3.7 moles of C₈H₁₁O₂