## Chem – Naming Ionic Compounds Part 2

What sections should I know before attempting to learn this section?

How do you use an ionic name to create the ionic compound?

Going in the other direction (taking the name and making the ionic compound), however, is a littler harder. First, you have to find the charges of the elements, and then you have to get them to total up to zero. How many of each element you need depends on how many each take to get to zero. In math, they call this concept the least common multiple.

Examples: Give the ionic compound from the name using a regular periodic table. Don’t forget to use the ion periodic table if you need it.  VIDEO Ionic Naming Examples 2.

 Lithium Phosphide Li3P Radium Iodide RaI2

VIDEO Ionic Naming Demonstrated Example 2: Give the ionic compound from the name using a regular periodic table. Don’t forget to use the ion periodic table if you need it.

Sodium Chloride

Step 1:

What is the symbol for Chloride?

 Cl 1 1 Total =

Step 2:

What is the ion of Chloride?

 Cl– 1 1 Total =

Step 3:

What is the symbol for Sodium?

 Na Cl– 1 1 Total =

Step 4:

What is the ion of Sodium?

 Na+ Cl– 1 1 Total =

Step 5:

What is the least common denominator between 1 and 1?

 Na+ Cl– 1 1 Total = +1 -1

Step 6:

What is the complete chemical formula?

VIDEO Ionic Naming Demonstrated Example 3: Give the ionic compound from the name using a regular periodic table. Don’t forget to use the ion periodic table if you need it.

Calcium Phosphide

Step 1:

What is the symbol for phosphorous?

 P 1 1 Total =

Step 2:

What is the charge for phosphorous?

 P3- 1 1 Total =

Step 3:

What is the symbol for calcium?

 Ca P3- 1 1 Total =

Step 4:

What is the charge for calcium?

 Ca2+ P3- 1 1 Total =

Step 5:

What is the least common denominator between 2 and 3?

 Ca2+ P3- 1 1 Total = +6 -6

Step 6:

How many phosphorous do you need to add up to a total of -6?

 Ca2+ P3- 1 P3- 1 Total = +6 -6

Step 7:

How many calcium do you need to add up to a total of +6?

 Ca2+ P3- Ca2+ P3- Ca2+ Total = +6 -6

Step 8:

What is the complete chemical formula?  