MDCAT Chemistry MCQ #623

In the synthesis of chloroethane from ethanol, why is thionyl chloride (SOCl2) considered superior to phosphorus pentachloride (PCl5) in a laboratory setting?

MDCAT Chemistry MCQ #623

  1. Question 1

    Q1. In the synthesis of chloroethane from ethanol, why is thionyl chloride (SOCl2) considered superior to phosphorus pentachloride (PCl5) in a laboratory setting?

    • A) PCl5 produces fewer byproducts during the reaction process.
    • B) SOCl2 produces gaseous byproducts that escape the reaction mixture.
    • C) PCl3 provides a higher percentage yield of alkyl halide.
    • D) SOCl2 is less corrosive than phosphorus-based halogenating agents.

    Answer: SOCl2 produces gaseous byproducts that escape the reaction mixture.

    Explanation: Thionyl chloride is preferred because its byproducts (SO2, HCl) are gases, unlike PCl5 which produces liquid POCl3 that requires distillation.