1. Chemical Formulas-Covalent
Chapter 6 Sections 5-6

2. Properties of Ionic Compounds
Most ionic compounds are solid at room temperature
Dissolve in water
Conduct electricity when in the molten state or dissolved in water
Very high melting points. (strongest bond)
Examples: Acids, bases and salts

3. Properties of Covalent Compounds
Can exist as gases, liquids, or solids depending on molecular mass or polarity
Usually have lower MP and BP than ionic compounds
Do not usually dissolve in water
Do not conduct electricity

4. Covalent Formula-2 nonmetals!
Uses prefixes with the ending –ide on the second element!
Phosphorous is a nonmetal
Name:
Trinitrogen
diphosphide
N3P2
2 phosphorous atoms
Nitrogen symbol
A Subscript: 3 nitrogen atoms

5. Molecular Formulas
AKA Special binary. These are binary compounds made up of two non-metals
These have a special set of rules used only when
______________ and ____________ combine.

6. Naming Molecular Compounds
Ask yourself-
Are there only two elements? if yes..
Is the first element not hydrogen? If yes..
Is the first element a nonmetal? If yes..
Congratulations! You have a special binary formula that uses the following prefixes and rules!
But only use these rules if you answered yes to the three questions above…

7. Binary Covalent Formulas
 Compounds between two nonmetals
 First element in the formula is named first.
 Second element is named as if it were an anion.
 Use prefixes
 Never use mono on the first element’s name
P2O5 = diphosphorus pentoxide

8. Prefixes for Molecular Formulas
1 mono
2 di
3 tri
4 tetra
5 pent
5 hex
7 hept
8 oct
9 non
10 dec
LEARN THESE

9. Examples Carbon dioxide CO2 Xenon hexaflouride XeF6
Dinitrogen Monoxide N2O
You try
Phosphorus trichloride CO
Carbon tetrachloride
Check answers

10. Naming Acids
These are the easiest and the trickiest set of rules to learn!
Get our your sheet from the last chapter, “Valences of common ions”
Look for the element Hydrogen at the start of the formula…
If you have two elements it’s one set of rules
If you have more it’s another set of rules.

11. Binary Acid - HX HX Hydro__x__ic acid Example HCl Hydrochloric acid
HBr Hydrobromic acid
H2S Hydrosulfic acid

12. Ternary Acid
Ignore the hydrogen and look at the polyatomic ion and its ending
Change the ending according to the following and add the word acid
If the anion name ends in -ate,
then the acid name ends in -ic or -ric.
If the anion name ends in -ite,
then the acid name ends in -ous.

13. Acid Names from Anion Acid Anion Acid Name HClO hypochlorite
hypochlorous acid
HClO2
chlorite
chlorous acid
HClO3
chlorate
chloric acid
HClO4
perchlorate
perchloric acid

14. Prior and proper practice makes perfect….
This unit absolutely requires that you practice using the naming rules!
That’s why there are several worksheets
These items also appears on the TAKS test, so I don’t want you to just learn it for the test and forget the information!

15. Answers to Sample Problems
PCl3
Carbon monoxide
CCl4
Back to Examples