Question

Give the name of each of the following simple binary ionic compounds. a. LiI b. \(\mathrm{MgF}_{2}\) c. \(\mathrm{SrO}\) d. \(\mathrm{AlBr}_{3}\) e. \(\mathrm{CaS}\) f. \(\mathrm{Na}_{2} \mathrm{O}\)

Short answer

a. Lithium Iodide b. Magnesium Fluoride c. Strontium Oxide d. Aluminum Bromide e. Calcium Sulfide f. Sodium Oxide

Step-by-step solution

Exercise a: LiI

Begin by identifying the elements present: - Li: Lithium, a metal, which will be the cation - I: Iodine, a nonmetal, which will be the anion Name the compound: 1. The name of the cation is "Lithium." 2. Change the ending of the name of the anion to "-ide": Iodine -> Iodide Combine the names, and the final name for LiI is "Lithium Iodide."

Exercise b: \(\mathrm{MgF}_{2}\)

Begin by identifying the elements present: - Mg: Magnesium, a metal, which will be the cation - F: Fluorine, a nonmetal, which will be the anion Name the compound: 1. The name of the cation is "Magnesium." 2. Change the ending of the name of the anion to "-ide": Fluorine -> Fluoride Combine the names, and the final name for \(\mathrm{MgF}_{2}\) is "Magnesium Fluoride."

Exercise c: \(\mathrm{SrO}\)

Begin by identifying the elements present: - Sr: Strontium, a metal, which will be the cation - O: Oxygen, a nonmetal, which will be the anion Name the compound: 1. The name of the cation is "Strontium." 2. Change the ending of the name of the anion to "-ide": Oxygen -> Oxide Combine the names, and the final name for \(\mathrm{SrO}\) is "Strontium Oxide."

Exercise d: \(\mathrm{AlBr}_{3}\)

Begin by identifying the elements present: - Al: Aluminum, a metal, which will be the cation - Br: Bromine, a nonmetal, which will be the anion Name the compound: 1. The name of the cation is "Aluminum." 2. Change the ending of the name of the anion to "-ide": Bromine -> Bromide Combine the names, and the final name for \(\mathrm{AlBr}_{3}\) is "Aluminum Bromide."

Exercise e: \(\mathrm{CaS}\)

Begin by identifying the elements present: - Ca: Calcium, a metal, which will be the cation - S: Sulfur, a nonmetal, which will be the anion Name the compound: 1. The name of the cation is "Calcium." 2. Change the ending of the name of the anion to "-ide": Sulfur -> Sulfide Combine the names, and the final name for \(\mathrm{CaS}\) is "Calcium Sulfide."

Exercise f: \(\mathrm{Na}_{2} \mathrm{O}\)

Begin by identifying the elements present: - Na: Sodium, a metal, which will be the cation - O: Oxygen, a nonmetal, which will be the anion Name the compound: 1. The name of the cation is "Sodium." 2. Change the ending of the name of the anion to "-ide": Oxygen -> Oxide Combine the names, and the final name for \(\mathrm{Na}_{2} \mathrm{O}\) is "Sodium Oxide."

Key concepts

Cation Naming

When naming binary ionic compounds, the first step is to identify the cation. Cations are positively charged ions that come from metal elements. These metals willingly lose electrons resulting in a positive charge. The name of the cation is straightforward. It is simply the name of the metal itself.

For example:

• In lithium iodide (LiI), the cation is lithium, a metal. So, we call it "Lithium."
• In magnesium fluoride ( MgF_{2} ), the cation is magnesium, so it is named "Magnesium."
• Similarly, in compounds like strontium oxide ( SrO ) or aluminum bromide ( AlBr_{3} ), the cations are named strontium and aluminum, respectively.

Remember, the cation's name remains unchanged from the name of the element as shown on the periodic table. Aim to identify and name the cation before moving to the next steps.

Anion Naming

After identifying and naming the cation in a binary ionic compound, you need to address the anion. Anions are negatively charged ions formed when nonmetals gain electrons. Unlike cations, the naming of anions involves a slight change.

The anion's name is derived from the root name of the nonmetal element. To name a simple anion, replace the element's ending with "-ide." Here are examples for further clarity:

• Iodine becomes iodide as in lithium iodide ( LiI ). The suffix "-ide" is added to the element name iodine.
• Fluorine is changed to fluoride in magnesium fluoride ( MgF_{2} ).
• Similarly, oxygen turns into oxide, bromine to bromide, and sulfur to sulfide in their respective compounds.

This alteration is a universal rule for naming simple anions in binary ionic compounds. Mastering this simple transformation is crucial for correctly naming these types of compounds.

Compound Naming Rules

Once both the cation and anion have been identified and named, the final step is to combine these names to form the name of the binary ionic compound. The naming process is systematic and simple, adhering to straightforward rules:

1. **Cation First**: Begin by writing the name of the cation. The metal component always precedes the nonmetal in both the formula and the name of a compound.

2. **Anion Follows**: Next, write the modified name of the anion (with the suffix "-ide").

Following these steps ensures that the compound name accurately represents the chemical formula. Let's reinforce these rules with an example:

• For the compound LiI , we start with the cation "Lithium" and then add the anion "Iodide," resulting in the name Lithium Iodide.
• For CaS , use "Calcium" for the cation and "Sulfide" for the anion, giving us the name Calcium Sulfide.

Practicing these rules will help you quickly and accurately name similar binary ionic compounds, enhancing your proficiency in chemistry naming conventions.