Difference Between Acid and Alkaline

Thekey differencebetween acid and alkaline is thatthephof acids lies below pH 7 whereas the pH of alkaline is above pH 7.

酸和根据s是化学方面的两个重要概念。它们具有矛盾的特性。碱是碱的子集。因此，它具有所有基本特征。此外，我们将在下面讨论各种方法可以区分酸和碱。

内容

1.Overview and Key Difference
2.什么是酸
3.What is Alkaline
4.并排比较 - 表格形式的酸与碱性
5.概括

什么是酸?

来自不同科学家的酸有几个定义。Arrhenius将酸定义为捐赠H的物质₃O⁺ions in the solution. Whereas, Bronsted- Lowry defines an acid as a substance that can donate a proton. However, Lewis acid definition is far more common than the above two. According to it, any electron pair acceptor is an acid. According to the Arrhenius or Bronsted-Lowry definition, a compound, to name it as an acid, should have hydrogen and the ability to donate it as a proton. But according to Lewis, there are molecules, which don’t possess hydrogen but can act as an acid. For example, BCl₃是刘易斯酸，因为它可以接受电子对。Alcoholis a Bronsted-Lowry acid because it can donate aproton但是，根据刘易斯的说法，这是一个基础。

Regardless of the above definitions, we normally identify an acid as a proton donor. Acids have a sour taste. Lime juice, vinegar are two acids we come across at our homes. They react with bases producing water, and also they react with metals to form H₂, thus increase metal corrosion rate. We can categorize acids into two classes, depending on their ability to dissociate and produce protons. They arestrong acids and weak acids.

强酸和弱酸

Strong acids like HCl, HNO₃can completely ionize in a solution to give protons. Weak acids like CH₃COOH可以部分分离以减少质子的量。KA是酸解离常数。它表明能够失去弱酸的质子。要检查物质是否为酸，我们可以使用多个指标，例如石榴纸或pH纸。在pH量表中，从1-6个酸表示（低于pH 7）。具有pH 1的酸非常强，随着pH值的增加，酸度降低。此外，酸将蓝色的石蕊变成红色。

什么是碱？

Alkaline is having pH above 7. Therefore, the pH of an alkaline substance lies above pH 7. Group 1 and group 2 elements, which we name as alkali metals and alkaline earth metals are common alkaline substances, and they give alkaline solutions when we dissolve them in water. Sodium hydroxide, potassium hydroxide, magnesium hydroxide, calcium carbonate are some of the examples of these alkaline substances.

Arrhenius defines the bases as the substances that produce OH^–in solutions. Above molecules form OH^–when we dissolve them in water, therefore, act as bases. Alkaline solutions react easily with acids producing water and salt molecules. They show a pH value higher than 7 and turn red litmus to blue. There are other bases except for alkaline bases like NH₃. They also have the same basic properties.

What is the Difference Between Acid and Alkaline?

酸和alkaline are two forms of compounds that we categorize according to the pH of them. Therefore, the key difference between acid and alkaline is that the pH of acids lies below pH 7 whereas the pH of alkaline is above pH 7. Moreover, acids can ionize to form protons or H⁺ions while alkaline compounds can ionize to form hydroxide ions. When considering the taste and texture of those two compounds, we can get another difference between acid and alkaline compounds. That is, acids taste sour and have a sticky feeling while alkaline tastes bitter and has a slippery feeling.

The below infographic summarizes the difference between acid and alkaline in tabular form.

总结-酸性和碱性

酸和alkalines have opposing chemical and physical properties due to their different chemical behaviours. The key difference between acid and alkaline is that the pH of acids lies below pH 7 whereas the pH of alkaline is above pH 7.

Reference:

1. Britannica, The Editors of Encyclopaedia. “Acid.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 27 Dec. 2017.Available here
2. “Alkaline | Definition of Alkaline in English by Oxford Dictionaries.” Oxford Dictionaries | English, Oxford Dictionaries.Available here

Image Courtesy:

1.“石榴石纸”化学感兴趣 - 自己的作品，（公共领域）通过Commons Wikimedia
2.”PH Scale”By Christinelmiller – Own work,(CC BY-SA 4.0)viaCommons Wikimedia