课程： 16.7 《亨利溶性法》

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选择节亨利的溶性定律

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亨利的溶性定律
How is sipping soda in outer space different than on Earth?
::在外层空间吸苏打水与地球有何不同?

Having a soft drink in outer space poses some special problems. Under microgravity, the carbonation could quickly dissipate if not kept under pressure . You can’t open the can or you will lose carbonation. So a special pressurized container has been developed to get around the problem of loss at low gravity.
::在外层空间喝软饮料会产生一些特殊问题。在微重力下,碳化如果不保持在压力下,就会迅速消散。您不能打开罐头,或者会失去碳化。因此开发了一个特殊的加压容器来克服低重力的损失问题。

Henry’s Law
::《亨利法》

Pressure has very little effect on the of solids or , but has a significant effect on the solubility of gases. Gas solubility increases as the partial pressure of a gas above the liquid increases. Suppose a certain volume of water is in a closed container with the space above it occupied by carbon dioxide gas at standard pressure. Some of the CO ₂ molecules come into contact with the surface of the water and dissolve into the liquid. Now suppose that more CO ₂ is added to the space above the container, causing a pressure increase. More CO ₂ molecules are now in contact with the water and so more of them dissolve. Thus the solubility increases as the pressure increases. As with a solid, the CO ₂ that is undissolved reaches an equilibrium with the dissolved CO ₂ , represented by the following equation.
::气体溶解度随着气体在液态增加以上的部分压力而增加。假设一定量的水在封闭容器中,其面积由标准压力下的二氧化碳气体占据,有些二氧化碳分子与水表面接触,溶解到液体中。现在,假设容器上方空间增加更多的二氧化碳,造成压力增加。现在,更多的二氧化碳分子与水接触,因此,溶解能力随着压力的增加而增加。与固体一样,未溶解的二氧化碳分子与溶解的CO2形成平衡,以以下方程式为代表。

$\begin{aligned} {CO}_{2} (g) ⇄ {CO}_{2} (a q) \end{aligned}$
$\begin{align*}\text{CO}_2(g) \rightleftarrows \text{CO}_2(aq)\end{align*}$
::CO2(g) CO2(aq)

At equilibrium, the rate of gaseous CO ₂ dissolving is equal to the rate of dissolved CO ₂ coming out of the solution.
::在平衡时,气体CO2溶解率等于溶解后溶出溶解的CO2溶解率。

When carbonated beverages are packaged, they are done so under high CO ₂ pressure so that a large amount of carbon dioxide dissolves in the liquid. When the bottle is opened, the equilibrium is disrupted because the CO ₂ pressure above the liquid decreases. Immediately, bubbles of CO ₂ rapidly exit the solution and escape out of the top of the open bottle. The amount of dissolved CO ₂ decreases. If the bottle is left open for an extended period of time, the beverage becomes “flat” as more and more CO ₂ comes out of the liquid.
::当碳化饮料包装后,在高CO2压力下进行包装,使大量二氧化碳溶解在液体中。当瓶子打开时,由于液体上方的CO2压力而使平衡中断。二氧化碳的泡沫立即从瓶子顶部迅速排出溶液并脱出。溶解的CO2减少量。如果瓶子长时间开放,饮料就会随着液体中越来越多的二氧化碳而“充气 ” 。

The relationship of gas solubility to pressure is described by Henry’s law , named after English chemist William Henry (1774-1836). Henry’s Law states that the solubility of a gas in a liquid is directly proportional to the partial pressure of the gas above the liquid. Henry’s law can be written as follows:
::以英国化学家威廉·亨利(William Henry)(1774-1836)命名的亨利法描述了气体溶解与压力之间的关系。亨利法规定,液体中气体溶解与液体上方气体的部分压力直接成正比。亨利法可以写如下:

$\begin{aligned} \frac{S_{1}}{P_{1}} = \frac{S_{2}}{P_{2}} \end{aligned}$
$\begin{align*}\frac{S_1}{P_1}=\frac{S_2}{P_2}\end{align*}$
::S1P1=S2P2

$\begin{align*}S_1\end{align*}$ and $\begin{align*}P_1\end{align*}$ are the solubility and the pressure at an initial set of conditions; $\begin{align*}S_2\end{align*}$ and $\begin{align*}P_2\end{align*}$ are the solubility and pressure at another changed set of conditions. Solubilities of gases are typically reported in g/L, as seen in sample problem 16.1.
::S1和P1是溶解性和在一组初始条件下的压力;S2和P2是另一组已改变条件下的溶解性和压力;气体的溶解性通常以克/升报告,如抽样问题16.1所示。

Sample Problem:
::问题:

The solubility of a certain gas in water is 0.745 g/L at standard pressure. What is its solubility when the pressure above the solution is raised to 4.50 atm? The temperature is constant at 20°C.
::某种气体在水中的溶解度在标准压力下为0.745克/升。当溶液上方的压力升至4.50摄氏度时,其溶解度是多少? 温度在20°C时是恒定的。

Step 1: List the known quantities and plan the problem.
::第1步:列出已知数量并规划问题。

Known
::已知已知

$\begin{align*}S_1=0.745 \ \text{g} / \text{L}\end{align*}$
::S1=0.745克/升

$\begin{align*}P_1=1.00 \ \text{atm}\end{align*}$
::P1=1.00 小时

$\begin{align*}P_2=4.50 \ \text{atm}\end{align*}$
::P2=4.50 小时

Unknown
::未知

$\begin{align*}S_2= \ ? \ \text{g} / \text{L}\end{align*}$
::S2=? 克/升

Substitute into Henry’s law and solve for _{$\begin{align*}S_2\end{align*}$} .
::取代亨利的法律解决S2

Step 2: Solve.
::步骤2:解决。

$\begin{aligned} S_{2} = \frac{S_{1} \times P_{2}}{P_{1}} = \frac{0.745 g/L \times 4.50 atm}{1.00 atm} = 3.35 g/L \end{aligned}$
$\begin{align*}S_2=\frac{S_1 \times P_2}{P_1}=\frac{0.745 \text{ g/L} \times 4.50 \text{ atm}}{1.00 \text{ atm}}=3.35 \text{ g/L}\end{align*}$
::S2=S1xP2P1=0.745克/Lx4.50 单位m1.00 单位m=3.35克/升

Step 3: Think about your result.
::步骤3:想想你的结果。

The solubility is increased to 4.5 times its original value according to the direct relationship.
::根据直接关系,溶解度提高到其原值的4.5倍。

Summary
::摘要

The pressure above a liquid affects the solubility of a gas in the liquid.
::液体上方的压力影响液体中气体的溶解性。

Review
::回顾

Does pressure affect the solubility of liquids and solids?
::压力是否影响液体和固体的溶解性?

If you increase the pressure of a gas above the liquid, how does that affect the amount of gas dissolved in the liquid?
::如果气体在液体之上增加压力,这如何影响液体溶解气体的数量?

What equilibrium is eventually reached?
::最终达到什么平衡?

Explore More
::探索更多

Use the resource below to answer the questions that follow.
::利用以下资源回答以下问题。

What affects the Henry’s law constant?
::亨利定律常数有何影响?

What do you need to be careful of in the way of units?
::你需要小心什么在单位的方式?

If we know the atmospheric pressure and the mole fraction of the gas, how do we calculate the partial pressure of the gas?
::如果我们知道气体的大气压力和摩尔部分, 我们如何计算气体的部分压力?

章节大纲

常规

亨利的溶性定律

How is sipping soda in outer space different than on Earth? ::在外层空间吸苏打水与地球有何不同?

Henry’s Law ::《亨利法》

Sample Problem: ::问题:

Summary ::摘要

Review ::回顾

Explore More ::探索更多

How is sipping soda in outer space different than on Earth?
::在外层空间吸苏打水与地球有何不同?

Henry’s Law
::《亨利法》

Sample Problem:
::问题:

Summary
::摘要

Review
::回顾

Explore More
::探索更多