Prepare for Microsoft Certification Exam AB-731: AI Transformation Leader

[0:00]In this lesson, we are going to learn about how to name and write formulas for acids. Specifically, we're going to learn about how to name binary acids and oxy acids and then how to write their formulas. So an acid is a compound that produces hydrogen ions when dissolved in water. In other words, when you place an acid into water, it dissociates and one of the ions that it dissociates into is a hydrogen ion. The general formula for an acid is HX where H represents the hydrogen ion and X represents an anion. So in other words, an acid is simply a hydrogen ion bonded to an anion. We're going to discuss two different types of acids in this lesson. First we're going to discuss binary acids, and then we're going to discuss oxy acids. A binary acid is an acid that contains only two elements, hydrogen and one other element, usually a halogen. An example of a binary acid is hydrochlori acid. This acid only contains hydrogen and chlorine, which are two different elements. Oxy acids on the other hand are acids that contain hydrogen, oxygen, and one other element. An example of an oxy acid is nitric acid. Notice that it contains hydrogen, oxygen, and nitrogen. So let's first discuss how to name binary acids. The first step to naming a binary acid is to begin the name of the acid with the prefix hydro. Then you're going to add the root of the second element. Finally, you're going to end the name with the suffix "ic" followed by the word acid. So let's apply these steps to a few examples. The first example is an acid with the chemical formula HF. The first step says to begin the name of the acid with the prefix hydro. Then we're going to add the root of the second element. In this case, the second element is fluorine, so the root is floor. Finally, we're going to end the name with the suffix "ic" followed by the word acid. So the name of this acid is hydrofloric acid. Let's move on to the next example, which is HCL. The first step says to begin the name of the acid with the prefix hydro. Then we're going to add the root of the second element. In this case, the second element is chlorine, so the root is chlor. Finally, we're going to end the name with the suffix "ic" followed by the word acid. So the name of this acid is hydrochloric acid. And lastly, let's look at the third example, which is H2S. Again, the first step is to begin the name of the acid with the prefix hydro. Then we're going to add the root of the second element. In this case, the second element is sulfur, so the root is sulfur. Finally, we're going to end the name with the suffix "ic" followed by the word acid. So the name of this acid is hydrosulfuric acid. So now that we've discussed how to name binary acids, let's discuss how to write formulas for binary acids. The first step to writing a formula for a binary acid is to determine the symbol and charge of the anion from the name of the acid. For example, if the acid is hydrochlori acid, then the anion would be chloride. Remember that if the acid has the prefix hydro and the suffix "ic," then it's a binary acid. Once you've done that, you're going to use the crisscross method to balance the charges of the hydrogen ion and the anion to write the formula for the acid. Let's apply these steps to a few examples. The first example is hydrobromic acid. The first step says to determine the symbol and charge of the anion from the name of the acid. In this case, the anion is bromide, which has the symbol BR and a charge of minus one. Then we're going to use the crisscross method to balance the charges of the hydrogen ion and the anion to write the formula for the acid. Remember that a hydrogen ion has a charge of plus one. So we're going to write the symbol for hydrogen, which is H, with a charge of plus one. Then we're going to write the symbol for bromide, which is Br, with a charge of minus one. We're going to take the magnitude of the charge of the hydrogen ion and bring it to the subscript of the bromide ion. Then we're going to take the magnitude of the charge of the bromide ion and bring it to the subscript of the hydrogen ion. When we do that, we get H one B R one. Remember that when the subscript is one, we don't write it. So the formula for hydrobromic acid is HBr. Let's move on to the next example, which is hydroiodic acid. Again, the first step is to determine the symbol and charge of the anion from the name of the acid. In this case, the anion is iodide, which has the symbol I and a charge of minus one. Then we're going to use the crisscross method to balance the charges of the hydrogen ion and the iodide ion to write the formula for the acid. So we're going to write the symbol for hydrogen, which is H, with a charge of plus one. Then we're going to write the symbol for iodide, which is I, with a charge of minus one. We're going to take the magnitude of the charge of the hydrogen ion and bring it to the subscript of the iodide ion. Then we're going to take the magnitude of the charge of the iodide ion and bring it to the subscript of the hydrogen ion. When we do that, we get H one I one. Again, since the subscript is one, we don't write it. So the formula for hydroiodic acid is HI. And lastly, let's look at the third example, which is hydrosulfuric acid. Again, the first step is to determine the symbol and charge of the anion from the name of the acid. In this case, the anion is sulfide, which has the symbol S and a charge of minus two. Then we're going to use the crisscross method to balance the charges of the hydrogen ion and the sulfide ion to write the formula for the acid. So we're going to write the symbol for hydrogen, which is H, with a charge of plus one. Then we're going to write the symbol for sulfide, which is S, with a charge of minus two. We're going to take the magnitude of the charge of the hydrogen ion and bring it to the subscript of the sulfide ion. Then we're going to take the magnitude of the charge of the sulfide ion and bring it to the subscript of the hydrogen ion. When we do that, we get H two S one. Again, since the subscript is one, we don't write it. So the formula for hydrosulfuric acid is H2S. So now that we've discussed how to name and write formulas for binary acids, let's discuss how to name oxy acids. Remember that oxy acids are acids that contain hydrogen, oxygen, and one other element. To name oxy acids, we're going to determine the name of the polyatomic anion. Then if the polyatomic anion ends in "ate," we're going to replace "ate" with "ic" followed by the word acid. If the polyatomic anion ends in "ite," then we're going to replace "ite" with "ous" followed by the word acid. Let's apply these steps to a few examples. The first example is an acid with the chemical formula HNO3. The first step says to determine the name of the polyatomic anion. In this case, the polyatomic anion is NO3, which is nitrate. Notice that nitrate ends in "ate." So we're going to replace "ate" with "ic" followed by the word acid. So the name of this acid is nitric acid. Let's move on to the next example, which is HNO2. Again, the first step is to determine the name of the polyatomic anion. In this case, the polyatomic anion is NO2, which is nitrite. Notice that nitrite ends in "ite." So we're going to replace "ite" with "ous" followed by the word acid. So the name of this acid is nitrous acid. And lastly, let's look at the third example, which is H2SO4. Again, the first step is to determine the name of the polyatomic anion. In this case, the polyatomic anion is SO4, which is sulfate. Notice that sulfate ends in "ate." So we're going to replace "ate" with "ic" followed by the word acid. So the name of this acid is sulfuric acid. So now that we've discussed how to name oxy acids, let's discuss how to write formulas for oxy acids. The first step to writing a formula for an oxy acid is to determine the symbol and charge of the polyatomic anion from the name of the acid. For example, if the acid is sulfuric acid, then the polyatomic anion is sulfate. Remember that if the acid has the suffix "ic," then the polyatomic anion ends in "ate." If the acid has the suffix "ous," then the polyatomic anion ends in "ite." Once you've done that, you're going to use the crisscross method to balance the charges of the hydrogen ion and the polyatomic anion to write the formula for the acid. Let's apply these steps to a few examples. The first example is perchloric acid. The first step says to determine the symbol and charge of the polyatomic anion from the name of the acid. In this case, the polyatomic anion is perchlorate, which has the chemical formula ClO4 and a charge of minus one. Then we're going to use the crisscross method to balance the charges of the hydrogen ion and the perchlorate ion to write the formula for the acid. So we're going to write the symbol for hydrogen, which is H, with a charge of plus one. Then we're going to write the chemical formula for perchlorate, which is ClO4, with a charge of minus one. We're going to take the magnitude of the charge of the hydrogen ion and bring it to the subscript of the perchlorate ion. Then we're going to take the magnitude of the charge of the perchlorate ion and bring it to the subscript of the hydrogen ion. When we do that, we get H one ClO4 one. Again, since the subscript is one, we don't write it. So the formula for perchloric acid is HClO4. Let's move on to the next example, which is chlorous acid. Again, the first step is to determine the symbol and charge of the polyatomic anion from the name of the acid. In this case, the polyatomic anion is chlorite, which has the chemical formula ClO2 and a charge of minus one. Then we're going to use the crisscross method to balance the charges of the hydrogen ion and the chlorite ion to write the formula for the acid. So we're going to write the symbol for hydrogen, which is H, with a charge of plus one. Then we're going to write the chemical formula for chlorite, which is ClO2, with a charge of minus one. We're going to take the magnitude of the charge of the hydrogen ion and bring it to the subscript of the chlorite ion. Then we're going to take the magnitude of the charge of the chlorite ion and bring it to the subscript of the hydrogen ion. When we do that, we get H one ClO2 one. Again, since the subscript is one, we don't write it. So the formula for chlorous acid is HClO2. And lastly, let's look at the third example, which is carbonic acid. Again, the first step is to determine the symbol and charge of the polyatomic anion from the name of the acid. In this case, the polyatomic anion is carbonate, which has the chemical formula CO3 and a charge of minus two. Then we're going to use the crisscross method to balance the charges of the hydrogen ion and the carbonate ion to write the formula for the acid. So we're going to write the symbol for hydrogen, which is H, with a charge of plus one. Then we're going to write the chemical formula for carbonate, which is CO3, with a charge of minus two. We're going to take the magnitude of the charge of the hydrogen ion and bring it to the subscript of the carbonate ion. Then we're going to take the magnitude of the charge of the carbonate ion and bring it to the subscript of the hydrogen ion. When we do that, we get H two CO3 one. Again, since the subscript is one, we don't write it. So the formula for carbonic acid is H2CO3.