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Ch.5 - Thermochemistry
Brown - Chemistry: The Central Science 15th Edition
Brown15th EditionChemistry: The Central ScienceISBN: 9780137542970당신이 사용하는 게 아니라요?교과서 변경
모든 교과서Brown 15th EditionCh.5 - Thermochemistry문제 42a
5장, 문제 42a

Without referring to tables, predict which of the following has the higher enthalpy in each case: (a) 1 mol CO2(s) or 1 mol CO2(g) at the same temperature

검증된 단계별 안내
1
Identify the states of matter for CO2: solid (s) and gas (g).
Recall that enthalpy is a measure of the total energy of a thermodynamic system, including internal energy and energy required to make room for it by displacing its environment.
Understand that gases generally have higher enthalpy than solids at the same temperature because they have higher kinetic energy and require more energy to maintain their state.
Consider the energy required for phase changes: transitioning from solid to gas (sublimation) requires energy input, indicating that the gaseous state has higher enthalpy.
Conclude that 1 mol CO2(g) has higher enthalpy than 1 mol CO2(s) at the same temperature.

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주요 개념

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Enthalpy

Enthalpy is a thermodynamic property that represents the total heat content of a system. It is defined as the sum of the internal energy and the product of pressure and volume. Enthalpy changes are crucial for understanding heat transfer during chemical reactions and phase changes, making it essential for predicting the stability and energy of substances in different states.
추천 영상:
가이드 코스
02:34
Enthalpy of Formation

Phase Changes

Phase changes refer to the transitions between solid, liquid, and gas states of matter. These changes involve energy transfer, typically in the form of heat, which affects the enthalpy of the substances. For example, when a solid transitions to a gas (sublimation), it absorbs energy, resulting in a higher enthalpy for the gaseous state compared to the solid state at the same temperature.
추천 영상:
가이드 코스
01:46
Entropy in Phase Changes

Gibbs Free Energy

Gibbs Free Energy (G) is a thermodynamic potential that measures the maximum reversible work obtainable from a thermodynamic system at constant temperature and pressure. It combines enthalpy and entropy to predict the spontaneity of processes. While not directly asked in the question, understanding Gibbs Free Energy helps contextualize why gases generally have higher enthalpy than solids, as they possess greater disorder and energy.
추천 영상:
가이드 코스
01:51
Gibbs Free Energy of Reactions
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