Answer: Sudden heating causes unequal/differential thermal expansion between inner and outer surfaces, creating stress that cracks the glass.
- A The inner surface of the glass undergoes a localized melting reaction at the exact point of contact with the inrushing hot water
- B Sudden heating causes unequal/differential thermal expansion between inner and outer surfaces, creating stress that cracks the glass
- C The sudden inrush of hot water exerts a momentarily much higher hydrostatic pressure directly against the tumbler inner wall
- D The glass tumbler actually contracts in overall volume rather than expanding outward when it is suddenly heated this way
Correct answer: B. Sudden heating causes unequal/differential thermal expansion between inner and outer surfaces, creating stress that cracks the glass
Explanation: Glass is a poor thermal conductor; rapid heating causes the inner surface to expand quickly while the outer surface remains cooler, and the resulting differential expansion creates stress that can crack the glass.
During a phase change (melting or boiling), temperature stays constant while heat is absorbed entirely as latent heat (Q=mL); temperature only rises again once the substance is fully in its new phase.
Concept context
Temperature scales, thermal expansion, calorimetry, and the three modes of heat transfer including radiation laws.