简单来说,能区分两个物质酸碱性强弱的叫做区分溶剂,否则就叫做拉平溶剂。题目中说的氢氧化钠和氢氧化钾同时溶解在水中,都会完全电离,这就是说二者被水这个溶剂拉平了,而表现出了相同的碱性。如果采用乙醇或液氨等作为溶剂,即可区分出二者碱性的强弱。
In short, the solvent that can distinguish the acidity and alkalinity of two substances is called distinguishing solvent, otherwise it is called flattening solvent. The sodium hydroxide and potassium hydroxide mentioned in the title will be completely ionized when they are dissolved in water at the same time, which means that they are leveled by the solvent of water and show the same alkalinity. If ethanol or liquid ammonia is used as solvent, the alkalinity of the two can be distinguished.
为了方便理解,你可以认为这里酸碱性的强弱指的是给出H+和OH-的能力,但是水接受这两个离子的能力是有上限的,180斤和200斤的胖子站在只能量到150斤的秤上,是比较不出谁更重的。
In order to facilitate understanding, you can think that the strength of acidity and alkalinity here refers to the ability to give H + and oh -, but there is an upper limit to the ability of water to accept these two ions. A fat man of 180 kg and 200 kg can't compare who is heavier when standing on a scale with an energy of only 150 kg.
碱的碱性强弱与溶液的碱性强弱这两个概念是不同的。应该是碱的碱性强弱比较。碱的碱性强弱与碱的电离程度有关,对于氢氧化钠和氢氧化钾这两种完全电离的强碱来说,由金属活泼性来判断,从这个角度,氢氧化钾比氢氧化钠的碱性强。而溶液的碱性强弱是由氢氧根离子浓度大小决定的,氢氧根离子浓度越大碱性越强,摩尔浓度相同的氢氧化钠溶液与氢氧化钾溶液的碱性是相同的。
The alkalinity of alkali is different from that of solution. It should be the alkalinity of alkali. The alkalinity of alkali is related to the ionization degree of alkali. For two fully ionized strong bases, sodium hydroxide and potassium hydroxide, it is judged by the metal activity. From this point of view, potassium hydroxide is more alkaline than sodium hydroxide. The alkalinity of the solution is determined by the concentration of hydroxyl ion. The greater the concentration of hydroxyl ion, the stronger the alkalinity. The alkalinity of sodium hydroxide solution with the same molar concentration is the same as that of potassium hydroxide solution.
氢氧化钾是以氯化钾水溶液进行电解,而氢氧化钠则是以氯化钠水溶液进行电解,二者只是原料不同(一个是KCl,一个是NaCl),和产品不同(一个是KOH,一个是NaOH),相同的是都要经过盐水精制、电解等工序,且电解槽的结构都基本一样,当然许多细节肯定有差异的。
Potassium hydroxide is electrolyzed with potassium chloride aqueous solution, while sodium hydroxide is electrolyzed with sodium chloride aqueous solution. They are only different in raw materials (one is KCl and the other is NaCl) and products (one is KOH and the other is NaOH). The same thing is that they all go through brine refining, electrolysis and other processes, and the structure of the electrolytic cell is basically the same. Of course, many details must be different.
氢氧化钾的摩尔质量大于氢氧化钠的摩尔质量;
The molar mass of potassium hydroxide is greater than that of sodium hydroxide;
当两者的物质的量浓度相同时,溶液的碱性相同;
When the amount and concentration of the two substances are the same, the alkalinity of the solution is the same;
氢氧化钾图片
Potassium hydroxide picture
当两者的溶液质量分数相同时,氢氧化钠溶液的碱性大于氢氧化钾的碱性;
When the mass fraction of both solutions is the same, the alkalinity of sodium hydroxide solution is greater than that of potassium hydroxide;
氢氧化钾的价格大于氢氧化钠,但配置相同碱性溶液时,需要氢氧化钾的的质量要大一些。
The price of potassium hydroxide is higher than that of sodium hydroxide, but when configuring the same alkaline solution, the quality of potassium hydroxide is higher.