Naming Binary Molecular Compounds

1. 9.3 Naming Binary Molecular Compounds • Carbon and oxygen combine to form carbon monoxide (CO) and carbon dioxide (CO2), but these two invisible gases are very different.

2. 9.3 Naming Binary Molecular Compounds • Sitting in a room with small amounts of CO2 in the air would not present any problems. If the same amount of CO were in the room, you could die of asphyxiation. A naming system that distinguishes between these two compounds is needed.

3. 9.3 Naming Binary Molecular Compounds • A prefix in the name of a binary molecular compound tells how many atoms of an element are present in each molecule of the compound. You MUST know these Prefixes

4. 9.3 Naming Binary Molecular Compounds • Some guidelines for naming binary molecular compounds: • Name the elements in the order listed in the formula. • Use prefixes to indicate the number of each kind of atom. • Omit the prefix mono- when the formula contains only one atom of the first element in the name. • The suffix of the name of the second element is -ide.

5. 9.3 Writing Formulas for BinaryMolecular Compounds • Writing Formulas for Binary Molecular Compounds • How do you write the formula for a binary molecular compound? • Use the prefixes in the name to tell you the subscript of each element in the formula. Then write the correct symbols for the two elements with the appropriate subscripts.

6. 9.3 Writing Formulas for BinaryMolecular Compounds • Silicon carbide is a hard material like diamond. The name silicon carbide has no prefixes, so the subscripts of silicon and carbon must be one. Thus, the formula for silicon carbide is SiC.

7. 9.3 Section Quiz. • Assess students’ understanding of the concepts in Section9.3.

8. 9.3 Section Quiz. • 1. Which of the following compounds is named INCORRECTLY? • CS2, carbon disulfide • BCl3, boron trichloride • IF7, iodine heptafluoride • PCl5, phosphorus hexachloride

9. 9.3 Section Quiz. • 2. Which of the following molecular compounds is named INCORRECTLY? • SbCl3, antimony trichloride • C2O5, dicarbon pentoxide • CF4, carbon tetrafluoride • H3As, hydrogen arsenide

10. 9.3 Section Quiz. • 3. The correct formula for tetraphosphorus trisulfide is • P3S4 • S3P4 • P4S3 • S4P3

11. Practicing Skills: Naming Chemical Compounds • Practicing Skills: Naming Chemical Compounds • How do you use a flowchart to write the name of a chemical compound? • Follow the arrows and answer the questions on the flowchart to write the correct name for a compound.

12. Practicing Skills: Naming Chemical Compounds For names of acids see regents ref tables

13. 9.5 • CuSO4 is an example from the flowchart. The compound will end in -ite or -ate. Cu is not part of Group A, so you must name the ions and use a Roman numeral to identify the charge of the transition metal. The name is copper(II) sulfate.

14. 9.4 • Practicing Skills: Writing Chemical Formulas • What four guidelines should you follow to write the formula of a chemical compound?

15. 9.5 Practicing Skills: Naming ChemicalCompounds • In writing a chemical formula from a chemical name, it is helpful to remember the following guidelines. • An -ide ending generally indicates a binary compound. • An -ite or -ate ending means a polyatomic ion that includes oxygen is in the formula.

16. Practicing Skills: Naming Chemical Compounds • Prefixes in a name generally indicate that the compound is molecular. • A Roman numeral after the name of a cation shows the ionic charge of the cation. 9.5

17. Section Quiz 9.5. • Assess students’ understanding of the concepts in Section 9.5.

18. 9.5 Practicing Skills: Naming Chemical Compounds Use periodic table for charges Use ref tables for polyatomic ions

19. Section Quiz 9.5. • 2. You want to write the chemical formula for iron(II) chloride. Based on Figure 9.22, after identifying symbols, what is the correct next step in the flowchart? • Group A elements • Roman numerals • Balance charges • Polyatomic ions

20. Section Quiz 9.5. • 3. Using the flowchart in Figure 9.20, if you determine that the name of an ion ends in -ite or -ate, the ion is a • polyatomic cation. • polyatomic anion. • transition metal cation. • group A anion.