Enthalpies of solution and hydration · 溶解焓和水合焓
| English | 中文 | Pinyin · 拼音 |
|---|---|---|
| enthalpy of solution/enˈθælpi ɒv səˈluːʃn/ | 溶解焓 | róng jiě hán |
| enthalpy of hydration/enˈθælpi ɒv haɪˈdreɪʃn/ | 水合焓 | shuǐ hé hán |
| exothermic/eɡzəˈðɜːmɪk/ | 放热 | fàng rè |
| lattice energy/ˈlætɪs ˈenədʒi/ | 晶格能 | jīng gé néng |
Dissolving, energetically
- Dissolving an ionic solid involves two enthalpy steps.
- Hydration releases energy; pulling the lattice apart costs it.
- A cycle links them to the enthalpy of solution 溶解焓.
有能量地溶解
- 溶解一个离子固体涉及两个焓步骤。
- 水合(hydration)释放能量;把晶格拉开消耗它。
- 一个循环把它们与溶解焓(enthalpy of solution)联系起来。
Enthalpy of solution lab · 溶解焓实验室
deltaHsol = lattice + hydration terms · deltaHsol = 晶格 + 水合项
Change hydration strength and see solution enthalpy shift. · 改变水合强度,看溶解焓移动。
The enthalpy change when one mole of gaseous ions dissolves in water is the enthalpy of ______. · 当一摩尔气态离子溶于水时的焓变是______焓。
More negative for smaller, more highly charged ions. · 对更小、电荷更高的离子更负。
Enthalpy of solution can be found from lattice energy and hydration enthalpies using Hess's law. · 溶解焓能用盖斯定律从晶格能和水合焓找到。
A Hess cycle links them. · 一个盖斯循环把它们联系起来。
The two changes
- enthalpy of hydration 水合焓 $\Delta H_{\text{hyd}}$: change when one mole of gaseous ions is surrounded by water (exothermic 放热).
- enthalpy of solution $\Delta H_{\text{sol}}$: change when one mole of solute fully dissolves.
Dissolving energy cycle links lattice energy 晶格能, hydration and solution
两个变化
- 水合焓 $\Delta H_{\text{hyd}}$:当一摩尔气态离子被水包围时的变化(放热)。
- 溶解焓 $\Delta H_{\text{sol}}$:当一摩尔溶质完全溶解时的变化。
溶解能量循环把晶格能、水合和溶解联系起来
The enthalpy change of hydration is: · 水合的焓变是:
Water molecules are attracted to the ions, releasing energy, so hydration is exothermic. · 水分子被离子吸引,释放能量,所以水合是放热的。
The dissolving cycle
To dissolve, you first pull the lattice apart, then hydrate the ions:
- Like lattice energy, $\Delta H_{\text{hyd}}$ is more exothermic for ions of higher charge and smaller radius.
溶解循环
要溶解,你先把晶格拉开,然后水合离子:
- 像晶格能一样,$\Delta H_{\text{hyd}}$ 对更高电荷和更小半径的离子更放热。
The enthalpy of solution is given by: · 溶解焓由以下哪个给出:
You reverse the lattice energy (to separate the ions) then add the hydration enthalpy. · 你逆转晶格能(以分离离子),然后加上水合焓。
The enthalpy of hydration is more exothermic for ions with: · 水合焓对有以下哪种的离子更放热:
Higher charge and smaller radius pull the water molecules in more strongly, releasing more energy. · 更高的电荷和更小的半径把水分子拉得更强,释放更多能量。
Linking the enthalpies
- Enthalpy of solution = (−lattice energy) + enthalpies of hydration of the ions.
- A Hess cycle links the three quantities.
联系这些焓
- 溶解焓 =(−晶格能)+ 离子的水合焓。
- 一个盖斯循环把这三个量联系起来。
You've got it
- hydration $\Delta H_{\text{hyd}}$ (exothermic): gaseous ions surrounded by water
- solution $\Delta H_{\text{sol}}$: one mole of solute dissolves
- the cycle: $\Delta H_{\text{sol}} = -\Delta H_{\text{latt}} + \Delta H_{\text{hyd}}$
- $\Delta H_{\text{hyd}}$ is more exothermic for higher charge and smaller radius
你掌握了
- 水合 $\Delta H_{\text{hyd}}$(放热):气态离子被水包围
- 溶解 $\Delta H_{\text{sol}}$:一摩尔溶质溶解
- 循环:$\Delta H_{\text{sol}} = -\Delta H_{\text{latt}} + \Delta H_{\text{hyd}}$
- $\Delta H_{\text{hyd}}$ 对更高电荷和更小半径更放热