In this video, we're going to introduce acids. Acids are any chemical that increases a solution's concentration of hydrogen ions or H+ ions. Recall that the concentration of hydrogen ions can be abbreviated with brackets like this, and it has H+ in the middle. Whenever we see brackets in science, it indicates the concentration of what's between the brackets. This is the concentration of hydrogen ions here. So acids will increase the concentration of hydrogen ions in solution.
If we look at the example below, at the addition of hydrochloric acid or HCl to water, we can see an example of an acid. Notice on the far left, we're showing four different molecules of hydrochloric acid or HCl, numbered 1, 2, 3, and 4. As the name implies, hydrochloric acid is an acid, which means that when added to water, it increases the concentration of hydrogen ions. When a hydrochloric acid molecule is added to water, it splits into two components: a hydrogen ion and a chloride anion. Each HCl molecule splits into H+ and Cl- when added to pure water.
Notice over here in this beaker, there are these chloride anions, three out of four since we have four HCl molecules, and we also have four hydrogen ions. Through the addition of HCl to pure water, we have an increase in the concentration of hydrogen ions. We have more hydrogen ions in the solution than what we had before. So, we can say that we have increased the hydrogen ion concentration. That is it for acids. Acids are any substance that will increase the concentration of hydrogen ions. The concentration of hydrogen ions is very important for biological processes, and we'll learn more about that as we move forward in our course.
In our next video, we're going to talk about bases. I'll see you all there.
