BINARY MOLECULAR NOMENCLATURE RULES

“Love”, Robert Indiana, American, 1967

Before we begin, I just wanted to take time to let you know about a substance that is quietly destroying the environment and disrupting world economies, yet nothing is being done about it: dihydrogen monoxide (DHMO.)

FACTS:

• In a study between 2005 and 2009, 3533 people died from Dihydrogen Monoxide (DHMO) inhalation during recreational use in the U.S.
• DHMO is the 3rd leading cause of unintentional injury-related deaths worldwide, accounting for 7% of all injury- related deaths. (388,000 annually)
• Please click on this link for more info: http://www.dhmo.org/facts.html

BINARY MOLECULAR (2 NONMETALS)

1. Name the least electronegative element first.
2. Change the last syllable of the second element to “-ide”.
3. Add appropriate prefix to element name to indicate the number of atoms of each element present.

BINARY MOLECULAR PREFIXES

1-mon(o)

2-di

3-tri

4-tetr(a)

5-pent(a)

​

6-hex(a)

7-hept(a)

8-oct(a)

9-non(a)

10-dec(a)

​

BINARY MOLECULAR PREFIXES

1-mon(o)

2-di

3-tri

4-tetr(a)

5-pent(a)

6-hex(a)

7-hept(a)

8-oct(a)

9-non(a)

10-dec(a)

Notice that the vowels at the end of each prefix (except for di- and tri-) are in parentheses. This is because sometimes you use the vowel and sometimes not. The general rule is: use the vowel if used with an element that starts with a consonant (e.g., tetrafluoride); don’t use the vowel if used with an element that starts with a vowel (e.g., tetroxide).

BINARY MOLECULAR PREFIXES

DO NOT USE MONO ON FIRST ELEMENT!!!

​

PRACTICE 1

Name the following compound:

​

N₂O

​

dinitrogen monoxide

PRACTICE 2

Name the following compound:

​

CS₂

​

carbon disulfide

PRACTICE 3

Name the following compound:

​

SF₆

​

sulfur hexafluoride

PRACTICE 4

Name the following compound:

​

P₂O₄

​

diphosphorus tetroxide

THAT’S IT!

Now do some practice on your own. The assignment is posted on today’s agenda. Good luck!