Chemistry is one of the most important subjects at school. The wonderful world of substances and compounds, as well as the colorful and interesting experiments that the teacher shows, fascinate all children, forcing them to show a certain interest in the mysterious science. In this article, we pay attention to the process of electrolytic dissociation, and more specifically to weak and strong electrolytes.
To give a detailed answer to the question of what relates to strong electrolytes and what refers to weak electrolytes, we must first understand what dissociation of substances is.
Electrolytic dissociation
Various chemical compounds, for example, salts or acids dissolve in water, decaying to elementary particles: ions, this reaction is also called electrical dissociation. Compounds that dissolve, decaying into ions, are in turn called electrolytes.
So are also called compounds that can conduct electric current, and substances that are not endowed with this ability, respectively, are called non-electrolytes.
The process of dissociation is reversible, therefore, the letter is indicated by two arrows with opposite directions, written under each other. The resulting solution has the ability to conduct electric current.
Electric current is the coordinated movement of free particles with a charge, which has a certain direction. Electric current in metals passes through relatively free electrons, but in this case we will not talk about metals.
In addition, the ions into which the substance decays have a different charge. Here it is necessary to introduce two more terms on this topic: cations and anions. Cations are ions with a positive charge, and anions, on the contrary, with a negative charge.
The quantitative characteristic of the process
Since in the future we will focus on water compounds, it is necessary to introduce the concept of solution. According to physical theory, a solution is the mechanical part of components without any permissible interaction of molecules. However, giving an answer to the question of what concerns strong electrolytes, this version has no explanation specifically for electrolytic solutions. Therefore, we turn to the chemical view of this concept.
A solution is a chemical reaction, confirmed, for example, by heat generation or by changing the color of a solution, between a solvent (in this case, water) and a substance dissolved in it (in this case, an electrolyte). Modern science believes that this concept can be characterized by both physical and chemical definitions, because both of them are essentially true.
In order to numerically characterize the dissociation of various compounds, it was decided to use the concept of “electrolytic degree of dissociation of a substance”, which helps to understand which substances belong to strong electrolytes and which to weak ones. This characterizing number is calculated by the formula as the partial number of molecules decaying into ions to their total amount in the substance. Accordingly, if this value is close to unity, then the compound refers to strong electrolytes, since the vast majority of molecules underwent dissociation. As a rule, in chemical reactions with strong electrolytes it is customary to write an equal sign, since it is not reversible.
Strong electrolytes
Strong electrolytes include:
- Water soluble salts. This information can be obtained by opening the solubility table.
- Inorganic acids related to strong electrolytes, such as H 2 SO 4 , HCl, HNO 3 and others.
- Hydroxides of metal compounds, as well as bases, such as LiOH, Ba (OH) 2 and others.
Weak electrolytes
Having decided what applies to strong electrolytes, it is worth talking about their opposite - weak electrolytes, poorly dissociated in water.
These include:
- Inorganic acids such as H 2 CO 3 , H 2 S, HNO 2 and others.
- Many organic acids.
- Hydroxides of metals that are not soluble in water. Information on this can be found by opening the solubility table.
- Water.
Conclusion
Let's hope that this article has been useful to you, and you have received a detailed answer to the question of what concerns strong electrolytes and what concerns weak electrolytes. In any case, we want to wish you success in further exploring the wonderful world of chemistry, which can seem like magic only at the very beginning. And with further training, you can independently work wonders, surprising everyone around you.