Answer:
The answer to your question is 98.9 %
Explanation:
Data
moles of methane = CHâ‚„ = 2.0
excess air
Percent yield = ?
mass of COâ‚‚ = 87 g
- Balanced chemical reaction
        CH₄  +  2O₂  ⇒  CO₂  +  2H₂O
   Reactants   Elements    Products
       1           C          1
       4          H          2
       4          O          2
- Calculate the molar mass of CHâ‚„
CHâ‚„ = 12 + 4 = 16 g
- Convert the moles to mass
           16 g of CH₄ ----------------- 1 mol
            x         -----------------  2 moles
            x = (2 x 16) / 1
            x = 32 g of CH₄
-Calculate the theoretical formation of COâ‚‚
           16 g of CH₄ ----------------- 44 g of CO₂
           32 g of CH₄ ----------------  x
              x = (32 x 44) / 16
              x = 88 g of CO₂
-Calculate the Percent yield
   Percent yield = Actual yield/Theoretical yield x 100
   Percent yield = 87/88 x 100
  Percent yield = 98.9 %
