Answer:
Explanation:
As per the law of conservation of mass all the mass of carbon present in the hydrocarbon weighing 112 g is present in the 328.5 g of carbon dioxide produced when the hydrocarbon was burned in air.
1) Calculate the mass of carbon in 328.5 g of carbon dioxide:
x / 328.5 g CO₂ = 12.011 g C / 44.009 g/mol ⇒ x = 86.65 g C
2) Calculate the percent mass of carbon:
= (89.65 / 112) × 100 = 80.04%
Round to three signifcant figures: 80.0%.