The Common-Ion Effect · 同离子效应
| English | 中文 | Pinyin · 拼音 |
|---|---|---|
| common-ion effect/ˈkɒmən ˈaɪɒn ɪˈfekt/ | 同离子效应 | tóng lí zi xiào yìng |
Crowding out a dissolving salt
- A salt dissolves less in water that already holds one of its ions.
- Add extra chloride, and silver chloride dissolves even less.
- The shared ion pushes the balance backward.
- It is Le Chatelier at work in a beaker.
把正在溶解的盐挤出去
- 盐在已经含有它某种离子的水中溶解得更少。
- 加入额外的氯离子,氯化银溶解得更少。
- 那个共有的离子把平衡推向逆向。
- 这是勒沙特列在烧杯里发挥作用。
The common-ion effect
- The common-ion effect 同离子效应 lowers a salt's solubility.
- It happens when the solution already contains one of its ions.
- The extra ion shifts the dissolving equilibrium backward.
同离子效应
- 同离子效应降低盐的溶解度。
- 它发生在溶液已经含有它某种离子时。
- 那额外的离子把溶解平衡推向逆向。
Adding a common ion to a saturated salt solution makes the salt... · 向饱和盐溶液中加入同离子会使该盐...
The common ion shifts the dissolving equilibrium backward. · 同离子使溶解平衡逆向移动。
The common-ion effect is a direct application of ____ Chatelier's principle. · 同离子效应是____Chatelier原理的直接应用。
It is Le Chatelier's principle applied to a solubility equilibrium. · 这是应用于溶解度平衡的勒夏特列原理。
Le Chatelier explains it
- Adding a product ion raises $Q$ above $K_{sp}$.
- The system shifts back, precipitating some solid.
- So less of the salt stays dissolved.
勒沙特列的解释
- 加入一种产物离子把 $Q$ 提到 $K_{sp}$ 之上。
- 系统逆向移动,析出一些固体。
- 所以更少的盐保持溶解。
Adding a common product ion raises $Q$ above $K_{sp}$, so the system... · 加入同产物离子使$Q$高于$K_{sp}$，因此系统...
With $Q > K_{sp}$, the reaction reverses, forming solid. · 带有$Q > K_{sp}$，反应逆向进行，形成固体。
Putting it to use
- Chemists add a common ion to force a salt out of solution.
- It is how you purify or recover a dissolved compound.
- Solubility drops sharply as the shared ion's concentration rises.
加以利用
- 化学家加入同离子,把盐逼出溶液。
- 这是提纯或回收溶解化合物的方法。
- 随着共有离子浓度升高,溶解度急剧下降。
Chemists can add a common ion to force a dissolved salt to precipitate. · 化学家可以加入同离子迫使溶解的盐沉淀。
The common-ion effect is used to recover or purify compounds. · 同离子效应用于回收或纯化化合物。
Does $\text{AgCl}$ dissolve more in pure water or in $\text{NaCl}$ solution?
- $\text{NaCl}$ adds extra $\text{Cl}^-$, a common ion.
- So $\text{AgCl}$ dissolves less in the $\text{NaCl}$ solution.
$\text{AgCl}$ 在纯水中溶解得多,还是在 $\text{NaCl}$ 溶液中?
- $\text{NaCl}$ 加入了额外的 $\text{Cl}^-$,一个同离子。
- 所以 $\text{AgCl}$ 在 $\text{NaCl}$ 溶液中溶解得更少。
The common-ion effect · 同离子效应
For AgCl -> Ag+ + Cl-, sort each addition by its effect on solubility. · 对于 AgCl -> Ag+ + Cl-，按其对溶解度的影响对每种添加物排序。
$\text{AgCl}$ dissolves less in $\text{NaCl}$ solution than in pure water because $\text{NaCl}$ adds... · $\text{AgCl}$在$\text{NaCl}$溶液中的溶解度小于纯水，因为$\text{NaCl}$添加了...
The shared $\text{Cl}^-$ pushes the equilibrium back toward solid. · 共享的$\text{Cl}^-$将平衡推回固体一侧。
The common-ion effect changes the value of $K_{sp}$. · 同离子效应改变了$K_{sp}$的值。
$K_{sp}$ is unchanged; only the amount dissolved changes. · $K_{sp}$保持不变；仅溶解量发生变化。
A common ion always decreases solubility, never increases it -- it shifts the dissolving equilibrium backward. $K_{sp}$ itself does not change; only the amount that dissolves does. And the effect grows stronger the more of the shared ion is already present.
同离子总是降低溶解度,绝不提高它——它把溶解平衡推向逆向。$K_{sp}$ 本身不变;只有溶解的量改变。而且已经存在的共有离子越多,效应越强。
The common-ion effect lowers a salt's solubility when the solution already holds one of its ions. That extra ion raises $Q$ above $K_{sp}$, shifting the dissolving equilibrium backward so less dissolves. $K_{sp}$ stays the same; only the solubility falls.
同离子效应在溶液已含有盐的某种离子时降低盐的溶解度。那额外的离子把 $Q$ 提到 $K_{sp}$ 之上,把溶解平衡推向逆向,使溶解得更少。$K_{sp}$ 保持不变;只有溶解度下降。