1. Chemical Names and Formulas
Chapter 9
Chemical Names and Formulas

2. Section 1
Naming Ions

3. Section 1 Learning Targets
9.1.1 – I can identify the charges of monatomic ions by using the periodic table, and name the ions – I can define a polyatomic ion and write the names and formulas of the most common polyatomic ions – I can identify the two common endings for the names of most polyatomic ions.

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

5. Cations
When the metals in Groups 1A, 2A and 3A lose electrons they form cations with positive charges equal to the group number.
The names of these ions are the same as the element name with ion after it.

6. Anions
Nonmetals of Groups 5A, 6A, and 7A gain electrons to form anions with negative charges.
The charge of any ion of a Group A nonmetal is determined by subtracting 8 from the group number.

7. Group 7A so 7-8=-1; 6A so 6-8=-2; 5A so 5- 8=-3
The names of these ions change. The endings are dropped and replaced by –ide ion (sulfur = sulfide ion).
Groups 4A and 8A elements do not usually form ions.

8. Examples:
Name the ions formed by these elements and classify them as anions or cations:
Selenium ____________________
Barium ____________________
Phosphorus ____________________

9. Examples: Name the following ions: I- ____________________

10. This table can be found on page 254

11. Ions of Transition Metals
The charges of the cations of many transition metal ions must be determined from the number of electrons lost.

12. Two methods – classical (-ous and – ic endings) or the stock system (roman numerals).
Preferred is the stock system because the roman numeral tells the charge.
So why do we use Roman numerals or the classical method anyway?

13. This table can be found on page 255

14. Examples: Name the following ions: Fe3+ ____________________
Cu+ ____________________
Mn4+ ____________________
Sn2+ ____________________
Pb4+ ____________________

15. Polyatomic Ions Polyatomic ion – composed of more than one atom.
The names of most polyatomic anions end in –ate or –ite.
There are very few positive polyatomic ions.

17. Examples:
Write the symbol or formula (including charge) for each of the following ions:
Ammonium ion ____________________
Chromate ion ____________________
Tin (II) ion ____________________
Nitrate ion ____________________

18. Examples: Name the following ions: OH- ____________________
Pb4+ ____________________
SO42- ____________________
O2- ____________________

19. Section 2
Naming and Writing Formulas for Ionic Compounds

20. Section 2 Learning Targets
9.2.1 – I can apply the rules for naming and writing formulas for binary ionic compounds – I can apply the rules for naming and writing formulas for compounds with polyatomic ions.

21. Binary Ionic Compounds
In the past anyone who created a compound named it.
Currently there is a system.
Antione Lavoisier decided it was too difficult to memorize unrelated names and formulas.

22. Naming Binary Ionic Compounds
Binary compound – compound of two elements and can be either ionic or molecular.
To name binary ionic compounds, place the name of the cation first followed by the anion name.

23. Examples: Write the names of the following binary ionic compounds:
NaCl ____________________
MgBr2 ____________________
SrO ____________________
Li2O ____________________
Be3N2 ____________________

24. For transition metals you need to figure the charge of the metal and put that in parentheses as a Roman numeral.

25. Examples: Write the names of the following binary ionic compounds:
SnO2 ____________________
Fe2O3 ____________________
MnO ____________________
MnO2 ____________________
Co3N2 ____________________

26. Writing Formulas for Binary Ionic Compounds
Write the symbol of the cation and then the anion.
Add what ever subscripts are needed to balance the charges.

27. Examples:
Write the formulas for the compounds formed from these pairs of ions:
Ba2+, S2- ____________________
Ca2+, N3- ____________________
Li+, O2- ____________________
Cu2+, I- ____________________

28. Examples: Write the formulas for these compounds:
Sodium iodide ____________________
Potassium sulfide ____________________
Calcium iodide ____________________

29. For transition metals the Roman numeral tells the charge on the metal cation.
Then the same as before, balance the charges.

30. Examples: Write the formulas for the following compounds:
Tin (IV) nitride ____________________
Copper (I) oxide ____________________
Copper (II) oxide ____________________
Lead (II) sulfide ____________________
Iron (III) oxide ____________________

31. Compounds with Polyatomic Ions
Write the symbol for the cation followed by the formula for the polyatomic ion and balance the charges.
HINT: if you need more than one polyatomic ion – use parenthesis.

32. Examples: Write the formula for the following compounds:
Ammonium nitride ____________________
Ammonium cyanide ___________________
Calcium carbonate ____________________
Tin (IV) sulfite ____________________
Magnesium phosphate __________________

33. Naming Compounds with Polyatomic Ions
To name a compound containing a polyatomic ion, state the cation first and then the anion, just as you did for binary ionic compounds.

34. Examples: Name the following compounds: Sn2(CO3)4 ____________________
Mg(CN)2 ____________________
Fe(NO3)3 ____________________
(NH4)3PO4 ____________________
CuSO4 ____________________

35. Section 3
Naming and Writing Formulas for Molecular Compounds

36. Section 3 Learning Targets
9.3.1 – I can interpret the prefixes in the names of molecular compounds in terms of their chemical formulas – I can apply the rules for naming and writing formulas for binary molecular compounds.

37. Naming Binary Molecular Compounds
Remember binary means 2.
Molecular compounds have covalent bonds – not ionic like previous sections.

38. A prefix in the name of a binary molecular compound tells you how many atoms of each element are present in each molecule of the compound.
Ending is still –ide so make sure you’re telling the difference between molecular and ionic.

40. Examples: Write the name for the following binary molecular compounds:
NCl3 ____________________
SO3 ____________________
NI3 ____________________
N2O3 ____________________
N2H4 ____________________

41. Writing Formulas for Binary Molecular Compounds
Use the prefixes in the name to tell you the subscripts of each element in the formula.
Then write the correct symbols for the two elements with the appropriate subscripts.

42. Examples:
Write the formulas for the following binary molecular compounds:
Phosphorus pentachloride __________________
Iodine heptafluoride ____________________
Chlorine trifluoride ____________________
Iodine dioxide ____________________
Diphosphorus trioxide ____________________

43. Section 4
Naming and Writing Formulas for Acids and Bases

44. Section 4 Learning Targets
9.4.1 – I can apply three rules for naming acids – I can apply the rules in reverse to write the formulas for acids – I can apply the rules for naming bases.

45. Naming Acids
Acid – a compound that contains one or more hydrogen atoms and produces hydrogen ions (H+) when dissolved in water.

47. Rules for Naming Acids
When the name of the anion (X) ends in –ide, the acid name begins with the prefix hydro-. The stem of the anion has the suffix –ic and is followed by the word acid.
HCl(aq) (X = chloride) is named hydrochloric acid.
H2S(aq) (X = sulfide) is named hydrosulfuric acid.

48. When the anion name ends in –ite, the acid name is the stem of the anion with the suffix –ous, followed by the word acid.
H2SO3(aq) (X = sulfite) is named sulfurous acid.

49. When the anion name ends in –ate, the acid name is the stem of the anion with the suffix –ic followed by the word acid.
HNO3(aq) (X = nitrate) is named nitric acid.

50. Examples: Write the names for the following acids:
HNO2 ____________________
HCN ____________________
HMnO4 ____________________
H2S ____________________
HClO4 ____________________

52. Writing Formulas for Acids
Use the rules for writing the names of acids in reverse to write the formulas for acids.

53. Examples: Write the formulas for the following acids:
Carbonic acid ____________________
Sulfurous acid ____________________
Hydroiodic acid ____________________
Nitrous acid ____________________
Phosphoric acid ____________________

54. Names and Formulas for Bases
Base – an ionic compound that produces hydroxide ions (OH-) when dissolved in water.
Bases are named in the same way as other ionic compounds.
The name of the cation is followed by the name of the anion.
Formulas are written the same as for ionic compounds.

55. Examples: Identify each compound as an acid or a base:
Ba(OH)2 ____________________
HClO4 ____________________
Fe(OH)3 ____________________
KOH ____________________

56. Examples: Write the names for the following bases:
Ba(OH)2 ____________________
LiOH ____________________
Pb(OH)2 ____________________
Mg(OH)2 ____________________
Al(OH)3 ____________________

57. Section 5
The Laws Governing Formulas and Names

58. Section 5 Learning Targets
9.5.1 – I can define the laws of definite proportions and multiple proportions – I can apply the rules for naming chemical compounds by using a flowchart – I can apply the rules for writing the formulas of chemical compounds by using a flowchart.

59. The Laws of Definite and Multiple Proportions
The rules for naming and writing formulas are possible because compounds form from the elements in predictable ways.
These ways are summed up in two laws: the law of definite proportions and the law of multiple proportions.

60. The Law of Definite Proportions
States that in samples of any chemical compound, the masses of the elements are always in the same proportions.

61. The Law of Multiple Proportions
States whenever the same two elements form more than one compound, the different masses of one element that combine with the same mass of the other element are in the ratio of small whole numbers.

62. Practicing Skills: Naming Chemical Compounds
Follow the arrows and answer the questions on the flow chart to write the correct name for a compound.

65. Examples: Write the names for the following compounds:
NaClO3 ____________________
HClO4 ____________________
KHSO4 ____________________
Cl2O ___________________

66. Examples: Write the names for the following compounds:
SnO2 ____________________
Ca(OH)2 ____________________
K2CrO4 ____________________
Fe(C2H3O2)3 ____________________
SiCl4 ____________________

67. Practicing Skills: Writing Chemical Formulas
An –ide ending generally indicates a binary compound.
Either ionic or covalent.
An –ite or –ate ending means a polyatomic ion that includes oxygen is in the formula.
An –ic or –ous ending shows that the compound may be an acid.

68. Practicing Skills: Writing Chemical Formulas
Prefix in a name generally indicate the compound is molecular.
A Roman numeral after the name of a cation shows the ionic charge of the cation.

71. Examples: Write the formulas for the following compounds:
Calcium bromide ____________________
Aluminum carbide ___________________
Tin (IV) cyanide ____________________
Strontium acetate ____________________
Silver chloride ____________________

72. Examples: Write the formulas for the following compounds:
Nitrogen dioxide ____________________
Lithium hydride ____________________
Sodium silicate ____________________
Acetic acid ____________________
Hydrochloric acid ___________________