2.8 – Naming Inorganic Compounds

1. 2.8 – Naming Inorganic Compounds AP Chemistry Summer Homework Chapter 2

2. Naming • There are almost an infinite number of ways in which element can combine in order to make compounds • Therefore, a systematic method is used so that we can easily name all compounds • We will focus on naming inorganic (all non-carbon containing) compounds in this lecture

3. Names and Formulas of Ionic Compounds: Cations • Cations formed from metal atoms have the same name as the metal • E.g.: Na+ is a sodium ion, Zn+2 is a zinc ion, etc. • If a metal can have multiple charges, the positive charge is indicated by a Roman numeral in parentheses following the name of the metal. • E.g.: Fe2+ = iron (II) ion, Cu+3 = copper (III) ion • Iron, cobalt, copper, tin, and lead are the most common metals that have multiple charges

4. REMEMBER – MEMORIZE YOUR POLYATOMIC IONS!

5. Names and Formulas of Ionic Compounds: Anions • The names of elements that are anions are formed by adding –ideto the end of the name • Cl- = Chloride ion • Br- = Bromide ion • O2- = Oxide ion

6. Names and Formulas of Ionic Compounds: Anions 2. Polyatomic ions that contain oxygen have names ending in either –ate or –ite -ate ending polyatomic have more oxygens than –ite ones!

7. Names and Formulas of Ionic Compounds: Anions • Sometimes oxygen binds to the same ion with increasing amount of oxygens(e.g. ClO4-, ClO3-, etc.) • These come in 4’s and the pattern is always: • Per_____ate = 4 oxygens • _______ate = 3 oxygens • _______ite = 2 oxygens • Hypo______ite = 1 oxygen • Example: • ClO4- = Perchlorate, ClO3-= Chlorate, ClO2- = Chlorite, ClO- = Hypochlorite

8. Names and Formulas of Ionic Compounds: Anions 3. Anions derived by adding H+ to an oxygen containing anions have the prefix of hydrogen or dihydrogen based on the number of H+ in the anion

9. Naming Ionic Compounds • To name ionic compounds, you always name the cation and then the anion.

10. Class Example Name the following compounds: • CaCl2 • Ba(OH)2 • Sodium hydroxide

11. Try It Out! • K2SO4 • FeCl3 • Cobalt (II) Nitrate

12. Names and Formulas for Acids • Recall, acids are compounds that donate a hydrogen ion to solution. • Acids are named differently than other compounds • Two rules when naming acids: • Acids containing anions that are only single elements are named by changing the –ide prefix on the anion to –ic and adding hydro in front of the anion and then adding acid at the end. • E.g. HCl is hydrochloric acid • Acids containing polyatomic ions are named by changing –ate to –ic and –ite to –ouson the anion and then adding acid at the end

13. Class Example • HBr • H2SO4 • HClO2

14. Try It Out! • HNO3 • HF

15. Naming Covalent Molecules (Non-Acids) • The process for naming covalent inorganic compounds requires the following rules: • The name of the element furthest left on the Periodic Table is written first • If both elements are in the same group, the larger one is written 1st • The name of the second element is given an –ide ending • Greek prefixes are used to show the number of atoms

16. Class Example • SiBr4 • Disulfur dichloride • NH3

17. Try It Out! 1. N2O 2. Tetraphosphorushexasulfide