<p>At 300 K and 1 atm, 10 mL of hydrocarbon required 55 mL of&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>O</mi><mn>2</mn></msub></math>&nbsp;for complete combustion and produced 40 mL&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><mi>C</mi><msub><mi>O</mi><mn>2</mn></msub></math>. The hydrocarbon is</p>