Naming Compounds and Writing Formulas

1. Naming Compounds and Writing Formulas

2. Metals and Nonmetals • For nomenclature purposes, metals are to the left of the stair step line and nonmetals are to the right.

3. Systematic Naming • A compound is made of two or more elements. • The name should tell us how many and what type of atoms.

4. Types of Compounds • The types of compounds you will learn how to name and draw are • ionic compounds (binary and ternary), • molecular compounds and • acids (binary and ternary).

6. Atoms and Ions • Atoms are electrically neutral. • They have the same number of protons and electrons. • Ions are atoms, or groups of atoms, with a charge. • Ions have a different numbers of electrons.

7. Anions • An anion is a _________ ion. • An anion has _______ electrons. • Nonmetals can gain electrons. • The charge is written as a superscript on the right. negative gained F1- Has gained ___ electron(s) 1 O2- Has gained ___ electron(s) 2

8. Cations • A cation is a _________ ion. • It is formed by _______ electrons. • There are more protons than electrons. • Metals form cations. positive losing K1+ Has lost ___ electron(s) 1 Ca2+ Has lost ___ electron(s) 2

9. Oxidation Numbers

10. IONIC COMPOUNDS

11. Naming Cations • For cations, if the charge is always the same (Group A) just write the name of the metal.

12. Naming Cations • Li1+ lithium • Li is the symbol for ________. • Lithium is a Group 1A metal, so the charge is always the same. Write the name of the metal. • Li1+ is called the ___________. lithium ion

13. Naming Cations • Sr2+ strontium • Sr is the symbol for __________. • Strontium is a Group 2A metal, so the charge is always the same. Write the name of the metal. • Sr2+ is called the _____________. strontium ion

14. Naming Cations • Transition metals (as well as tin and lead) can have more than one type of charge. • Indicate the charge with Roman numerals in parenthesis. • Zinc (Zn2+) and silver (Ag1+), although transition metals, only have one possible charge. Roman numerals ARE NOT used for zinc and silver.

15. Naming Cations • Fe2+ • Fe is the symbol for ______. iron • Iron is a transition metal, so the charge is not always the same. Write the name of the metal, indicating the charge with Roman numerals in parenthesis. • Fe2+ is called the ___________. iron (II) ion

16. Naming Cations • Pb2+ • Pb is the symbol for ______. lead • Lead is a Group 4A metal, and the charge is not always the same. Write the name of the metal, indicating the charge with Roman numerals in parenthesis. • Pb2+ is called the ___________. lead (II) ion

17. Problem 1) Name the following cations. a) Ca2+ Calcium ion b) Al3+ Aluminum ion c) Sn4+ Tin (IV) ion

18. Problem • Name the following ions. d) Na1+ Sodium ion e) Fe3+ Iron (III) ion Copper (I) ion f) Cu1+

19. Naming Anions • Naming monatomic anions is always the same. • Change the element ending to – ide • Example: F1- • F is the symbol for fluorine, F1- is called fluor ide. ine.

20. Naming Anions • Cl- • Cl is the symbol for _________. chlorine • Chlorine is a Group 7A nonmetal, so the charge is always the same (-1). • Cl- is called the ____________. chloride ion

21. Naming Anions • O2- • O is the symbol for _________. oxygen • Oxygen is a Group 6A nonmetal, so the charge is always the same (-2). • O2- is called the __________. oxide ion

22. Problem 2) Name the following anions. a) S2- sulfide ion b) Br- bromide ion

23. Problem 2) Name the following anions. c) N3- nitride ion d) Se2- selenide ion

24. Ionic Compounds • In the formula for an ionic compound, the symbol of the cation is written before that of the anion. • Subscripts, or small numbers written to the lower right of the chemical symbols, show the numbers of ions of each type present in a formula unit.

25. Naming Binary Ionic Compounds • Binaryionic compounds are composed of a metal bonded with a nonmetal. • Name the metal ion using a Roman numeral in parenthesis if necessary. • Follow this name with the name of the nonmetal ion.

26. Problem 3) Name the following binary ionic compounds. a) NaCl sodium chloride b) Ca3P2 calcium phosphide

27. Problem • Name the following binary ionic compounds. c) CuO Copper (II) oxide d) SnBr2 Tin (II) bromide

28. Problem • Name the following binary ionic compounds. e) Fe2S3 Iron (III) sulfide f) AlF3 Aluminum fluoride

29. Problem • Name the following binary ionic compounds. g) KCl Potassium chloride h) Na3N Sodium nitride

30. Problem • Name the following binary ionic compounds. i) CrN Chromium (III) nitride j) PbO2 Lead (IV) oxide

31. Writing Formulas for Cations • Write the formula for the metal. • If a Roman numeral is in parenthesis use that number for the charge. Indicate the charge with a superscript. • If no Roman numeral is given, find the Group A metal on the periodic table and determine the charge from the column number.

32. Writing Formulas for Cations • Nickel (II) ion • ____ is the symbol for nickel. Ni • Nickel is a transition metal, which is the reason why the charge with Roman numerals in parenthesis was included. • The formula for the nickel (II) ion is _____. Ni2+

33. Writing Formulas for Cations • Gallium ion • ____ is the symbol for gallium. Ga • Gallium is a Group 3A metal and its charge is always the same (+3). • The formula for the gallium ion is ______. Ga3+

34. Problem 4) Write the formulas for the following cations. Mg2+ a) Magnesium ion Cu2+ b) Copper (II) ion K1+ c) Potassium ion

35. Problem • Write the formulas for the following ions. Ag1+ d) Silver ion Cr6+ e) Chromium (VI) ion Hg2+ f) Mercury (II) ion

36. Writing Formulas for Anions • Write the formula for the nonmetal. • Find the Group A nonmetal on the periodic table and determine the charge from the column number.

37. Writing Formulas for Anions • Phosphide • ___ is the symbol for phosphorus. P • Looking at the periodic table and finding phosphorus, the oxidation number (charge) can be determined. • The formula for phosphide is _____. P3-

38. Writing Formulas for Anions • Bromide • ___ is the symbol for bromine. Br • Looking at the periodic table and finding bromine, the oxidation number (charge) can be determined. • The formula for bromide is _____. Br1-

39. Problem 5) Write the formulas for the following anions. As3- a) arsenide Te2- b) telluride

40. Problem • Write the formulas for the following anions. I1- c) iodide ion d) carbide ion C4-

41. Writing Formulas for Ionic Compounds • Oxidation numbers can be used to determine the chemical formulas for ionic compounds. • If the oxidation number of each ion is multiplied by the number of that ion present in a formula unit, and then the results are added, the sum must be zero.

42. Writing Formulas for Binary Ionic Compounds • Write the symbol for the metal. Determine the oxidation number from either the column number or the Roman numeral and write it as a superscript to the right of the metal’s symbol.

43. Writing Formulas for Binary Ionic Compounds • To the right of the metal’s symbol, write the symbol for the nonmetal. Determine the oxidation number from the column number and write it as a superscript to the right of the nonmetal’s symbol.

44. Writing Formulas for Binary Ionic Compounds • Example: potassium fluoride + - K F

45. Writing Formulas for Binary Ionic Compounds • If the two oxidation numbers add together to get zero, the formula is a one-to-one ratio of the elements.

46. Writing Formulas for Binary Ionic Compounds • Example: potassium fluoride + - K KF F

47. Writing Formulas for Binary Ionic Compounds • Example: aluminum sulfide 3+ 2- Al S

48. Writing Formulas for Binary Ionic Compounds • If the two oxidation numbers DO NOT add together to get zero, you will need to “criss-cross” the superscripts. These numbers now become subscripts.

49. Writing Formulas for Binary Ionic Compounds • Example: aluminum sulfide 3+ 2- Al S 2- 3+

50. Writing Formulas for Binary Ionic Compounds • Omit all positive and negative signs and omit all 1’s.