Entropy change · 熵变
| English | 中文 | Pinyin · 拼音 |
|---|---|---|
| disorder/dɪˈsɔːdə/ | 无序 | wú xù |
| entropy/ˈentrəpi/ | 熵 | shāng |
Measuring disorder 无序
- Entropy 熵 ($S$) measures the number of ways particles and their energy can be arranged.
- More ways = more disorder.
- A change that increases disorder has a positive $\Delta S$.
测量无序
- 熵(entropy,$S$)测量颗粒和它们的能量能被排列的方式的数目。
- 更多的方式 = 更多的无序。
- 一个增加无序的变化有一个正的 $\Delta S$。
Entropy change lab · 熵变实验室
deltaS = products disorder - reactants disorder · deltaS = 产物无序 - 反应物无序
Increase disorder and see entropy change become more positive. · 增加无序,看熵变变得更正。
Entropy is a measure of: · 熵是以下哪种的量度:
More ways to arrange particles/energy means higher entropy (more disorder). · 排列颗粒/能量的更多方式意味着更高的熵(更多无序)。
Entropy increases when a solid melts or a gas is formed. · 当一个固体融化或一个气体形成时熵增加。
More disorder means higher entropy. · 更多无序意味着更高的熵。
When entropy rises
| Change | Sign of $\Delta S$ |
|---|---|
| solid → liquid → gas (or dissolving) | positive |
| a rise in temperature | positive |
| a reaction making more gas molecules | positive |
| a reaction making fewer gas molecules | negative |
Entropy rises from solid to liquid to gas
熵何时上升
| 变化 | $\Delta S$ 的符号 |
|---|---|
| 固体 → 液体 → 气体(或溶解) | 正 |
| 温度的上升 | 正 |
| 一个制造更多气体分子的反应 | 正 |
| 一个制造更少气体分子的反应 | 负 |
熵从固体到液体到气体上升
Which change has a positive entropy change? · 哪个变化有一个正的熵变?
Melting increases disorder (solid → liquid), so ΔS is positive; the others decrease disorder. · 融化增加无序(固体 → 液体),所以 ΔS 是正的;其他的减少无序。
A reaction that produces more gas molecules than it uses has: · 一个制造比它使用更多气体分子的反应有:
More gas molecules means more disorder, so ΔS is positive. · 更多气体分子意味着更多无序,所以 ΔS 是正的。
Match each entropy idea. · 匹配每个熵概念。
Each item links the term to its correct meaning. · 每一项把术语链接到它正确的含义。
Calculating ΔS
- Use the standard entropies given in the data.
An instant cold pack cools by an endothermic dissolving process — driven by the increase in entropy.
计算 ΔS
- 使用数据中给出的标准熵。
一个速冷袋通过一个吸热的溶解过程冷却——由熵的增加驱动。
The standard entropy change of a reaction is: · 一个反应的标准熵变是:
ΔS° = ΣS°(products) − ΣS°(reactants). · ΔS° = ΣS°(产物) − ΣS°(反应物)。
Predicting entropy change
- Entropy increases when more gas molecules are formed or a solid becomes liquid/gas.
- A reaction making more moles of gas has a positive ΔS.
预测熵变
- 当形成更多气体分子或一个固体变成液体/气体时,熵增加。
- 一个制造更多摩尔气体的反应有一个正的 ΔS。
You've got it
- entropy = number of ways to arrange particles/energy (more = more disorder)
- $\Delta S$ is positive for solid→liquid→gas, dissolving, higher temperature, or more gas molecules
- calculate it: $\Delta S^{\ominus} = \sum S^{\ominus}(\text{products}) - \sum S^{\ominus}(\text{reactants})$
你掌握了
- 熵 = 排列颗粒/能量的方式的数目(更多 = 更多无序)
- $\Delta S$ 对固体→液体→气体、溶解、更高温度,或更多气体分子是正的
- 计算它:$\Delta S^{\ominus} = \sum S^{\ominus}(\text{products}) - \sum S^{\ominus}(\text{reactants})$