Question

Calculate the mass (in g) of O2 consumed in the complete combustion of 76.5 g sample of C4H8O. (Hint, write the balanced equation.)

Answer 1

187g of O₂

Step-by-step explanation:

The combustion of C₄H₈O produce:

C₄H₈O + ¹¹/₂ O₂ → 4CO₂ + 4H₂O

The molecular mass of C₄H₈O is:

12,01g/mol × 4 + 1,01g/mol×8 + 16,00g/mol×1 = 72,12g/mol

Using molecular mass, moles of C₄H₈O in 76,5g are:

76,5g × (1mol / 72,12g) = 1,06 moles of C₄H₈O.

As 1 mole of C₄H₈O reacts with ¹¹/₂ moles of O₂ (Balances equation), the moles of O₂ that react are:

1,06 moles of C₄H₈O × (¹¹/₂ moles of O₂ / 1 mole of C₄H₈O) = 5,83 moles of O₂. As molecular mass of O₂ is 16,0g/mol×2 = 32,0g/mol. The mass of oxygen consumed in the complete combustion of the sample is:

5,83 moles of O₂ × (32,0g / 1mol) = 187g of O₂

I hope it helps!