1. Naming of Ionic Compounds Packet #15

2. Introduction An atom that has lost/gained electrons is considered to be an ion Cation Lost one or more electrons Positive charge Anion Gained one or more electrons Negative charge

3. NAMING IONS

4. Introduction Monatomic ion consist of a single atom with a positive or negative charge resulting from the loss or gain of one or more electrons.

5. NAMING IONS Anions

6. Introduction Remember, anions are formed when an atom gains one or more electrons while cations are formed when an atom has lost one or more electrons. The number of electrons added /lost determines what the charge the atom has.

7. Anions The charge of any ion of Group A nonmetal is determined by subtracting 8 from the group number.

8. Monatomic Anion—Naming The name of simple anions is obtained by adding –ide to the root of the atom name. Flourine F + e - = F - Flouride Bromine Br + e - = Br - Bromide Anions that have gained two electrons, oxide (O 2- ) and sulfide (S 2- ) for example, are named in the similar manner.

9. NAMING IONS Cations

10. Groups 1, 2 & 3 When the metals in groups 1A, 2A and 3A lose electrons, they form cations with positive charges equal* to their group number. The metals of Group 1A, 2A and 3A consistently form cations of 1 +, 2 + and 3 + respectively.

11. Monatomic Ion—Cation Naming Simple cations borrow their names from the names of the elements. K + Potassium ion Ca + Calcium ion

12. IONS OF TRANSITION METALS

13. Ions of Transition Metals Many of the transition atoms form more than one cation with different ionic charges. The charges of the cations of many transition atoms must be determined from the number of electrons that are lost.

14. Ions of Transition Metals I Iron Forms two common cations Fe 2+ Iron II ion Fe 3+ Iron III ion Tin, lead, copper, zinc and mercury Can also produce cations of different charges.

15. Naming Transition Elements Ions An older, useful method for naming cations, uses a root word with different suffixes at the end of the word. Ferrum is Latin for iron…therefore the root for iron is ferr-.

16. Naming of Transition Elements Ions II The suffix -ous is used to name the cation with the lower of the two cations. The suffix –ic is used to name the cation with the higher of the two cations. Ferrous iron Fe 2+ Ferric iron Fe 3+

17. Naming of Transition Elements Ions III

18. POLYATOMIC IONS

19. Polyatomic Ions Introduction A polyatomic ion is composed of more than one atom. Polyatomic ions are tightly bound group of atoms that behave as a single unit and carry a charge.

20. Naming of Polyatomic Ions I The names of most polyatomic anions end in –ite or –ate.

21. Naming of Polyatomic Ions II Sometimes the same two or three elements combine in different ratios to form polyatomic ions. Notice the endings Examine the charge Note the number of oxygen atoms that the ion contain. There should be a pattern.

22. Naming of Polyatomic Ions III The charge in each polyatomic ion in a given pair is the same. The -ite ending indicates the polyatomic with one less oxygen atom than the -ate ending. However, it does not tell how many oxygen atoms there are in the ion

23. Common Polyatomic Ions

24. System of Writing Formula of an Ionic Compound Write the symbol and charges for the cation and the anion Write the symbols for the ions side by side, beginning with the cation. To determine how to get a neutral compound, look for the lowest common multiple of the charges on the ions. For example, the lowest common multiple of 3 and 2 is 6. Fe 3+ Iron (III) O 2- Oxide The lowest common multiple of 3 and 2 is 6. Therefore, the formula should indicate six positive charges and six negative charges. Fe 2 O 3 For 6 positive charges, you need two Fe 2+ For 6 negative charges, you need three O 2-

25. System of Naming an Ionic Compound (Binary Ionic Compounds) The name is made up of two words The name of the cation Followed by the name of the anion NaCl Cation Sodium Anion Chloride Sodium chloride CuCl 2 Cation Copper (II) Anion Chloride Copper (II) chloride Al 2 S 3 Cation Aluminum Anion Sulfide Aluminum sulfide

26. System of Naming Polyatomic Ions Name the cation Recall that a cation is simply the name of the element Name the anion Remember, one must determine the charge of the anion to determine whether it receives–ite or –ate. K 2 CO 3 Cation Potassium Anion Has a charge of -2 CO 3 -2 has a name of carbonate The polyatomic ion’s name is thus potassium carbonate.

27. REVIEW