Answer:
95.4g
Explanation:
Given parameters:
Mass of carbon dioxide = 84g
Unknown:
Mass of oxygen = ?
Solution:
To solve this problem, we will simply work backward from the known to the unknown specie.
We first must write the balanced equation of the reaction;
2C₈H₁₈ + 25O₂ → 16CO₂ + 18H₂O
Now, convert the mass of CO₂ to number of moles;
Number of moles = [tex]\frac{mass}{molar mass}[/tex]
Molar mass of CO₂ = 12 + 2(16) = 44g/mol
Number of moles = [tex]\frac{84}{44}[/tex] = 1.91moles
From the balanced equation,
16 moles of CO₂ is produced by 25 moles of O₂
1.91 mole of CO₂ will be produced by [tex]\frac{1.91 x 25}{16}[/tex] = 2.98mole of O₂
Now, we convert this moles of Oxygen gas to mass;
Mass of O₂ = number of moles x molar mass
= 2.98 x 2(16)
= 95.4g
