Answer to Question #21123 in Inorganic Chemistry for Danielle Louise Akerson
Regarding phase changes, which of the following statements is false?
a) Sublimation is an endothermic process.
b) Deposition is an exothermic process.
c) Crystallization is an exothermic process.
d) Vaporization is an endothermic process.
e) None of the above answers is the correct answer.
a) - Correct. Sublimation is the conversion of a solid directly to a gas without going through the liquid state. Sublimation is always an endothermic process, since energy must be supplied to overcome the intermolecular forces that hold molecules together as a solid.
b) - Correct. Deposition is a process of phase change of a matter from gas phase to solid phase directly. Since it is the reverse process of sublimation, it is exothermic.
c) - Correct. The crystallization is a process of the formation of new bonds. The formation of new bond is a low energy state and therefore when new stable bonds are formed between atoms, energy is released. That is why crystallization is exothermic process.
d) - Correct. Vaporization is the conversion of a liquid to a gas. Vaporization is an endothermic process, since energy must be supplied to overcome the intermolecular forces that hold molecules together as a liquid.
e) - False. Since all statements above are correct, this statement is false.