A 0.271 -g sample of an unknown vapor occupies 294 mL at 140⁰ C and 847 mmHg. The empirical formula of the compound is CH₂. What is the molecular formula of the compound? (R = 0.08206L.atm/K.mol).
A. C₆H₁₂
B. CH₂
C. C₄H₈
D. C₂H₄
E. C₃H₆