1. Naming Binary Molecular Compounds
9.3
Naming Binary Molecular Compounds
C. Molecular Compounds
1. Naming Binary molecular compounds guidelines:
a. Name the elements in the order listed in the formula.
b. Use prefixes to indicate the number of each kind of atom.

2. Naming Binary Molecular Compounds
9.3
Naming Binary Molecular Compounds
i. Omit the prefix mono- if formula contains only one atom of the first element in the name.
ii. The suffix of the name of the second element is -ide.
2. Writing Formulas: prefixes in the name to tell you the subscript of each.
a. Guidelines:

3. b. Examples: Silicon carbide > SiC Potasium sulfate > K2SO4
9.5
i. An -ide ending indicates a binary compound.
ii. An -ite or -ate ending means a polyatomic ion that includes oxygen is in the formula.
iii. Prefixes indicates that the compound is molecular.
iv. Roman numeral shows the ionic charge of the cation.
b. Examples: Silicon carbide > SiC
Potasium sulfate > K2SO4
Fe(III) hydroxide > Fe(HO)3

4. Naming
Compounds
Given a
Formula
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5. Writing a
Compound’s Formula
Given a Name
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6. CFU
1. The law of definite proportions states that in samples of any chemical compound, the elements are always in the same proportion by
mass.
volume.
group number.
period number.

7. CFU
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

8. CFU
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.

9. CFU
4. Which of the following compounds is named INCORRECTLY?
a. CS2, carbon disulfide
b. BCl3, boron trichloride
c. IF7, iodine heptafluoride
d. PCl5, phosphorus hexachloride

10. CFU
5. Which of the following molecular compounds is named INCORRECTLY?
a. SbCl3, antimony trichloride
b. C2O5, dicarbon pentoxide
c. CF4, carbon tetrafluoride
d. H3As, hydrogen arsenide

11. CFU
6. The correct formula for tetraphosphorus trisulfide is
a. P3S4
b. S3P4
c. P4S3
d. S4P3

12. Proficiency Practice
181. Organic compounds are molecular compounds that contain carbon (C). They often have hydrogen (H), nitrogen (N), sulfur (S) and phosphorus (P). Identify the formula for organic compound Methane. a. (NH3) b. (PO4) c. (CH4) d. (SO2)
Answer C

13. Proficiency Practice
182. The compound water is represented by the formula H2O. Water is the only compound with this formula because a. only water contains atoms of the elements hydrogen and oxygen. b. atoms of hydrogen and oxygen are identical to each other in a reaction. c. atoms can never be created or destroyed by physical or chemical reactions. d. a specific compound always has the same relative numbers and kinds of atoms.
ANSWER d