Solutions and Mixtures · 溶液与混合物
| English | 中文 | Pinyin · 拼音 |
|---|---|---|
| solute/ˈsɒljuːt/ | 溶质 | róng zhì |
| solvent/ˈsɒlvənt/ | 溶剂 | róng jì |
| solution/səˈluːʃn/ | 溶液 | róng yè |
| molarity/məʊˈlærɪti/ | 摩尔浓度 | mó ěr nóng dù |
When one thing vanishes into another
- Stir sugar into tea and it disappears -- but it is still there.
- The sweet, clear liquid tastes uniform everywhere.
- One substance has spread evenly through another.
- We measure exactly how crowded that spread is.
当一样东西消失在另一样里
- 把糖搅进茶里,它消失了——但它仍然在那儿。
- 那甜甜的、清澈的液体到处尝起来都一样。
- 一种物质均匀地散布在另一种之中。
- 我们精确地测量这份散布有多密。
Solute and solvent
- A solution 溶液 is a uniform mixture of two or more substances.
- The solute 溶质 is what dissolves; the solvent 溶剂 does the dissolving.
- In salt water, salt is the solute and water is the solvent.
溶质与溶剂
- 溶液是两种或更多物质的均匀混合物。
- 溶质是被溶解的;溶剂是进行溶解的。
- 在盐水里,盐是溶质,水是溶剂。
In salt water, the salt is the... · 在盐水中，盐是...
The dissolved substance is the solute; water is the solvent. · 被溶解的物质是溶质；水是溶剂。
Measuring concentration
- Molarity 摩尔浓度 measures concentration:
- More solute per litre means a more concentrated solution.
测量浓度
- 摩尔浓度衡量浓度:
- 每升溶质越多,溶液越浓。
Dissolve $2\ \text{mol}$ of solute to make $4\ \text{L}$ of solution. The molarity (in M)? · 溶解$2\ \text{mol}$溶质制成$4\ \text{L}$溶液。摩尔浓度（单位M）是多少？
$M = \text{moles}/\text{liters} = 2/4 = 0.5\ \text{M}$.
Dilute and concentrated
- Adding solvent dilutes a solution, lowering $M$.
- Removing solvent or adding solute concentrates it, raising $M$.
- Dilution keeps the moles of solute the same: $M_1V_1 = M_2V_2$.
稀与浓
- 加入溶剂稀释溶液,降低 $M$。
- 移走溶剂或加入溶质使它变浓,提高 $M$。
- 稀释保持溶质的摩尔数不变:$M_1V_1 = M_2V_2$。
Concentration links moles and volume · 浓度联系摩尔数和体积
Molarity is moles of solute per litre of solution: at fixed concentration, moles scale with volume. · 摩尔浓度是每升溶液中溶质的摩尔数：在固定浓度下，摩尔数随体积缩放。
Dilute $100\ \text{mL}$ of $2\ \text{M}$ solution to $200\ \text{mL}$. The new molarity (in M)? · 将$100\ \text{mL}$的$2\ \text{M}$溶液稀释至$200\ \text{mL}$。新摩尔浓度（单位M）是多少？
From $M_1V_1 = M_2V_2$, $2\times100 = M_2\times200$, so $M_2 = 1\ \text{M}$. · 从$M_1V_1 = M_2V_2$, $2\times100 = M_2\times200$得出，所以$M_2 = 1\ \text{M}$。
Diluting a solution with more solvent keeps the number of moles of solute the same. · 用更多溶剂稀释溶液时，溶质的摩尔数保持不变。
You only add solvent, so the solute moles are unchanged. · 你只添加了溶剂，因此溶质摩尔数未变。
Removing solvent from a solution makes it more . · 去除溶液中的溶剂会使其变得更。
Less solvent for the same solute raises the molarity. · 相同溶质下溶剂减少会提高摩尔浓度。
Dissolve $0.5\ \text{mol}$ of salt in enough water to make $2\ \text{L}$.
- $M = \dfrac{\text{moles}}{\text{liters}} = \dfrac{0.5}{2} = 0.25\ \text{M}$.
- Add water to $4\ \text{L}$ and the molarity halves to $0.125\ \text{M}$.
把 $0.5\ \text{mol}$ 盐溶于足量水中,配成 $2\ \text{L}$。
- $M = \dfrac{\text{moles}}{\text{liters}} = \dfrac{0.5}{2} = 0.25\ \text{M}$。
- 加水到 $4\ \text{L}$,摩尔浓度减半到 $0.125\ \text{M}$。
Molarity is moles of solute divided by litres of... · 摩尔浓度等于溶质摩尔数除以...的升数。
It uses the total volume of solution, not just the solvent. · 它使用的是溶液的总体积，而不仅仅是溶剂。
Molarity uses litres of solution, not litres of solvent -- the final total volume. Diluting changes the concentration but not the moles of solute, which is why $M_1V_1 = M_2V_2$. And "concentrated" just means high molarity, not necessarily saturated.
摩尔浓度用的是溶液的升数,而不是溶剂的升数——即最终的总体积。稀释改变浓度但不改变溶质的摩尔数,这正是 $M_1V_1 = M_2V_2$ 的原因。而且"浓"只是指摩尔浓度高,不一定是饱和。
A solution is a uniform mixture where a solute dissolves in a solvent. Its concentration is the molarity $M = \text{moles} / \text{litres of solution}$. Adding solvent dilutes it (moles unchanged, so $M_1V_1 = M_2V_2$); adding solute concentrates it.
溶液是均匀的混合物,其中溶质溶解在溶剂里。它的浓度是摩尔浓度,即溶质的摩尔数除以溶液的升数。加入溶剂稀释它(摩尔数不变,所以 $M_1V_1 = M_2V_2$);加入溶质使它变浓。