Q. Which of the following processes is endothermic?
✅ Correct Answer: (C)
Sublimation of dry ice (CO2 solid → gas)
Explanation: Sublimation (solid to gas) requires input of energy — it's endothermic. Freezing and condensation release heat (exothermic). Formation of an ionic lattice from gaseous ions (lattice formation) releases energy (exothermic lattice energy). Hence sublimation is the correct endothermic process among the options.
Explanation by: Sikhar Chaudhary
Sublimation (solid to gas) requires input of energy — it's endothermic. Freezing and condensation release heat (exothermic). Formation of an ionic lattice from gaseous ions (lattice formation) releases energy (exothermic lattice energy). Hence sublimation is the correct endothermic process among the options.