1. Unit 4: Chemical Nomenclature Section 1: Binary Compounds and Polyatomic Ions

2. Nomenclature Chemical naming system ▫ Two major types of naming groups  Ionic Compounds  Covalent Compounds

3. Ionic Compounds Bond that is formed between a cation and an anion (metal and a nonmetal). ▫ Three categories of Ionic compounds  Simple Binary compounds  Binary compounds with polyatomic ions  Binary compounds with stock system ions

4. Simple Binary Compounds Formed with only two parts ▫ A positive ion (cation) and a negative ion (anion)

5. Naming Binary Compounds Use the criss-cross method to make the formula. Write the name of the 1 st element – cation - (capitalized) Add the 1 st part of the name of the 2 nd element – anion - (not capitalized) End the 2 nd element with “ide” ▫ Example: NaCl Sodium and Chlorine Sodium chloride

6. Let’s Practice!

7. Binary Compounds with Polyatomic Ions Polyatomic Ion - A group of two or more elements that stay together and act as one ion ▫ Example: NH 4 +1  Nitrogen and 4 Hydrogen are combined into one ion with a total +1 charge

8. Common Polyatomic Ions NH 4 +  Ammonium NO 2 -  Nitrite NO 3 -  Nitrate SO 3 2-  Sulfite SO 4 2-  Sulfate OH -  Hydroxide PO 3 3-  Phosphite PO 4 3-  Phosphate CO 3 2-  Carbonate

9. Naming Binary Compounds with Polyatomic Ions Follow the same rules for how binary compounds are named However, use the EXACT name of the polyatomic ion (DO NOT CHANGE TO -ide!!!!!!) In many cases, you place parentheses around the polyatomic ion in the formula

10. Examples of Binary Compounds with Polyatomic Ions Sodium and Nitrate ▫ Formula: Na +1 and NO 3 -1  NaNO 3  Because there are 1 + and 1 -, nothing else is done; You do NOT need parentheses here because the charge is canceled ▫ Name: Sodium nitrate

11. Calcium and Phosphate ▫ Formula: Ca 2+ and PO 4 3-  Ca 3 (PO 4 ) 2  The parentheses shows that the entire phosphate ion gets doubled (VERY IMPORTANT) ▫ Name: Calcium phosphate Examples of Polyatomic Compounds

12. Let’s practice!!!