Question

Compare how entropy changes for the following two systems: System A: A gas and a solid react to form a new solid product. System B: Rubbing alcohol evaporates on the skin.

Answer 1

Answer:

In system A: A gas and a solid react to form a new solid product. the system entropy decreases.

In System B: Rubbing alcohol evaporates on the skin. liquid alcohol is converting to gas by evaporation so the system entropy increases.

Explanation:

Entropy  is a thermodynamic quantity measure the degree of disorder of a certain system.

Gases have larger entropy compared to liquids  which is larger than solids.

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(A) When a gas convert to a solid, its entropy decreases. ... because solids have less energy and entropy than solids.

So, in system A: A gas and a solid react to form a new solid product. the system entropy decreases.

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(B) Any chemical reaction that increases the number of gas molecules also increases entropy.

So, in System B: Rubbing alcohol evaporates on the skin. liquid alcohol is converting to gas by evaporation so the system entropy increases

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