🔍 Key Concepts

• Boiling point of mixtures vs. pure substances • Effect of non‑volatile substances (like oil) dissolved in a refrigerant • Relationship between boiling temperature and pressure in refrigeration systems

💭 Think About

• Is the oil acting like part of the refrigerant that can boil, or is it more like a non‑boiling impurity at normal system temperatures? • When you dissolve a non‑volatile substance in a liquid, what usually happens to the liquid’s boiling point at the same pressure? • If the refrigerant is ‘contaminated’ with oil, will it be easier or harder for it to start boiling at that same pressure?

✅ Before You Answer

• Recall how boiling point changes when salt is added to water at the same pressure as a real‑world analogy. • Decide whether oil is volatile or non‑volatile at normal refrigerant boiling conditions. • Confirm whether any answer choice that says "no effect" on boiling point can be consistent with basic thermodynamics of mixtures.