Naming Ionic Compounds - Online Tutor, Practice Problems & Exam Prep

Understanding ionic compounds is crucial in chemistry, as they consist of a cation (positive ion) and an anion (negative ion). Cations can be metals or the ammonium ion (NH₄⁺), while anions are typically nonmetals or negatively charged polyatomic ions. When naming these compounds, the cation is named first, followed by the anion, with nonmetals adopting an "-ide" suffix. Transition metals require Roman numerals to indicate their charge. Recognizing base names for nonmetals aids in accurate naming, ensuring clarity in chemical communication.

Naming Ionic Compounds

Naming ionic compounds is going to be an incredibly important skill that you'll have to utilize for the remainder of your chemistry career. Now before we can name ionic compounds, it's first important to understand what are the components that make up an ionic compound. Recall, an ionic compound contains a positive ion called a cation. And one way to remember that cations are positive is here, this t can be seen as a positive charge associated with them, and this positive ion is connected to a negative ion called an anion. This is important to remember because a lot of times we may mistakenly say that an ionic compound is simply a metal with a nonmetal. That is not true, as an ionic compound fundamentally is a positive ion with a negative ion. The cation could be represented by a metal or could also be represented by a polyatomic ion that possesses a positive charge. And remember, the polyatomic ions, there are only two that possess a positive charge. One of them being the mercury (I) ion, but that already fits under the whole idea of being a metal. The other polyatomic ion that is positive is the ammonium ion. Remember, the ammonium ion is NH4+. Our cations are a metal with a positive charge or the ammonium ion which has a positive charge, and the anion is represented by a nonmetal or also a polyatomic ion that possesses a negative charge.

When it comes to naming ionic compounds, remember these fundamental components that make them up:

- Cations are typically metals or certain polyatomic ions with positive charges. - Anions are typically nonmetals or other polyatomic ions with negative charges.

Understanding this distinction is key as we proceed into naming ionic compounds. To be able to spot them, you have to remember they are a positive ion connected to a negative ion.

Naming Ionic Compounds

When it comes to naming an ionic compound, there's a certain number of steps you have to follow in order to name the compound successfully. Now if we take a look here, step 0. Step 0 is the most important thing to remember. When it comes to ionic compounds, we're always going to write them as cation first, followed by anion second. And that's the way we kind of want to keep things consistent. Step 1, we're going to start out with a cation since it's written first. With the cation, the metal always keeps its name and is written first. Now, part of this deals with the charge. If the metal possesses multiple charges, we must use a Roman numeral to describe its positive charge. So remember, if you don't recall this, go back to our videos on the periodic table and charges. Remember, the main group elements for the most part possess one type of charge, so they wouldn't require a Roman numeral. It's the transition metals for the most part that possess multiple charges. Because of that, we have to specify which one of them we are talking about. Am I talking about the manganese 2 ion or am I talking about the manganese 5 ion? So again, if you don't remember this, go back to my videos on the periodic table and charges. So if it possesses multiple charges, we use a Roman numeral. If the metal possesses one charge, just one type of charge, then we don't have to worry about a Roman numeral. For example, aluminum. Aluminum is in group 3. Group 3 has a charge of plus 3. Aluminum is not going to have any other type of positive charge, so I don't have to give it a Roman numeral. Now for the anion, if a nonmetal is used, it keeps its base name, but has its ending changed to ide. Now recall, the base name is just the beginning of the nonmetal's name that is unchanged. In the next video, we're going to take a look at the different types of nonmetals and what exactly are their base names following this definition. So click on to the next video and let's take a look at some base names of nonmetals.

Naming Ionic Compounds

Now remember, the base name is just the beginning of the nonmetal's name that is unchanged. So if we take a look here, we have our nonmetals, and we try to group them as best as we can in terms of the periodic table. So we have hydrogen in group 1a, boron in group 3a. These are in 4a. These are in 5a. These are in 6a, and of course, our halogens in 7a. Now remember, the base name again is the beginning of the nonmetal's name that is unchanged. So for hydrogen, its base name is hydro. Boron, it's bor. Carbon is carb. Silicon is sili, nitrogen is nitro, phosphorus is phospho, oxygen is just ox. Now again, we can just add suffix endings to them, but these are just the base names. Sulfur is sulf, then we have selenium which is selen, tellurium is tellur, and then we've covered the halogens when discussing the oxyhalogens or halogenoxy anions. So we know that it's chlor, brom, and iod. So these will be the base names for nonmetals when it comes to ionic compounds. Now step 3 is just if we're dealing with a polyatomic ion in any way, if it's present, it always just keeps its name. So if our ionic compound possesses a phosphate group, then it's just phosphate. Now keep these steps in mind when we're presented with any type of ionic compound and asked to determine its name.

Naming Ionic Compounds Example 1

In this example question, it asks you to provide the name for the following compound, Ca and Cl. Alright. So Ca is calcium, and Cl is chlorine. We know that the metal keeps its name and is written first, so we have calcium. But we have to think about whether calcium possesses multiple charges. Calcium is in Group 2A on the periodic table. Remember, metals in Group 2A all have a +2 charge. Because calcium possesses only one charge, it does not require a Roman numeral. So its name would just be calcium. Then we have chlorine. Remember, for the nonmetal, we keep its base name, which is chlor, but then we add "ide" to the end of the name. So CaCl₂ would be called calcium chloride.

Provide the name for the following compound:Al(BrO₄)₃

• A. aluminum hypobromite
• B. aluminum bromite
• C. aluminum bromide
• D. aluminum bromate
• E. aluminum perbromate

Provide the name for the following compound:CoCO₃

• A. cobalt carbonate
• B. cobalt (II) carbonate
• C. cobalt carbonite
• D. cobalt (III) carbonite

Here’s what students ask on this topic:

What are the steps to name an ionic compound?

To name an ionic compound, follow these steps:

1. Write the cation first, followed by the anion.

2. Name the cation. If it is a metal with a fixed charge, use its elemental name. If it has multiple charges (usually transition metals), indicate the charge with a Roman numeral.

3. Name the anion. For nonmetals, use the base name and change the ending to '-ide'. For polyatomic ions, use their standard names.

Example: NaCl is named sodium chloride, and Fe₂(SO₄)₃ is named iron(III) sulfate.

How do you determine the charge of a transition metal in an ionic compound?

To determine the charge of a transition metal in an ionic compound, look at the overall charge balance. The total positive charge from the cation(s) must equal the total negative charge from the anion(s). For example, in Fe₂O₃, oxygen has a -2 charge. With three oxygens, the total negative charge is -6. To balance this, each iron must have a +3 charge, making the compound iron(III) oxide.

What is the significance of Roman numerals in naming ionic compounds?

Roman numerals in naming ionic compounds indicate the charge of transition metals that can have multiple oxidation states. For example, iron can form Fe²⁺ and Fe³⁺. To distinguish between these, we use Roman numerals: FeCl₂ is iron(II) chloride, and FeCl₃ is iron(III) chloride. This ensures clarity in chemical communication.

How do you name ionic compounds with polyatomic ions?

When naming ionic compounds with polyatomic ions, the cation is named first, followed by the polyatomic ion. The polyatomic ion retains its standard name. For example, NaNO₃ is named sodium nitrate, and (NH₄)₂SO₄ is named ammonium sulfate. The naming rules for cations and anions still apply, ensuring proper identification.

What are the base names for common nonmetals in ionic compounds?

The base names for common nonmetals in ionic compounds are derived from the beginning of their elemental names. For example:

Hydrogen: hydro

Boron: bor

Carbon: carb

Nitrogen: nitr

Oxygen: ox

Phosphorus: phosph

Sulfur: sulf

Chlorine: chlor

Bromine: brom

Iodine: iod

These base names are used with the '-ide' suffix when naming anions, such as chloride (Cl^-) and oxide (O^2-).