1. OB: molecular compounds, naming and formulas, and determining how for form molecular compounds using selected oxidation states. Periodic tables mandatory now, smile, this is easier than the rest of the compounds we’ve looked at

2. Ionic compounds form when positive cations combine in proper ratio with negative anions, attracting each other because of opposite charge. The compounds must have a cation combining with anions (+ except for that weird ammonium) all cations are metals. With molecular compounds, the easy way to spot them is that there are NO METALS. Molecular compounds form when 2 or more nonmetals bond together,in proper ratios. There are NO ions, no ionic bonds either. They combine by sharing electrons which we’ll learn about later on in the year. They have their own naming system, which is easy if you can count to ten in Latin. If you can’t, I will teach you in a few slides.

3. CO 2 CO HCl NH 3 CH 4 H 2 O C 8 H 18 There are NO METALS ever in molecular compounds.

4. When two or more non metals bond together they form a molecule. A molecule is the smallest part of a molecular compound. The bonds that hold these atoms together is called a covalent bond. When 2 or more ions bond, they make ionic bonds, and they form into FORMULA UNITS. NaCl does not come in molecules, since it does not exist as a single particle. It’s in crystals, or dissolved in water.

5. NAMING RULES FOR MOLECULAR COMPOUNDS If you can remember what CO, CO 2, and H 2 O are, the naming rules are easy carbon monoxide, carbon dioxide + dihydrogen monoxide First name rule: a single atom? Say just the atom name a multiple atom? Say a prefix first Second name rule: always use a prefix

6. 1 MONO 2 DI 3 TRI 4 TETRA 5 PENTA 6 HEXA 7 HEPTA 8 OCTO 9 NON 10 DECA

7. Using the 2 rules, and the Latin Prefixes, let’s name these 10 example molecules. You will have to name any molecular compound with up to 10 atoms of any kind. HF CS 2 SO 3 CCl 4 PF 5 SF 6 Cl 2 O 8 I 4 O 9 N 2 F 10

8. Hopefully you got these all correct… HF CS 2 SO 3 CCl 4 PF 5 SF 6 Cl 2 O 8 I 4 O 9 N 2 F 10 Hydrogen monofluoride Carbon disulfide Sulfur trioxide Carbon tetrachloride Phosphorous pentafluoride Sulfur hexafluoride Dichlorine octoxide Tetraiodine nonoxide Dinitrogen decafluoride First name rule for single atom is say that atom name. Multiple atoms in first name gets a prefix. Second name rule says always use a prefix.

9. We will practice names to formulas first… Write the formulas for each named molecule: Phosphorous tribromide ____________ Diphosphorous trioxide ____________ Oxygen difluoride _____________ Dihydrogen monoxide ______________ Nitrogen monoxide ______________

10. We will practice names to formulas first… Write the formulas for each named molecule: Phosphorous tribromide PBr 3 Diphosphorous trioxide P 2 O 3 Oxygen difluoride OF 2 Dihydrogen monoxide H 2 O Nitrogen monoxide NO

11. Now in reverse, name these formulas with prefixes… NO 2 _________________________ CI 4 _________________________ N 2 0 _________________________ SO 3 _________________________ N 2 O 5 _________________________ HCl _________________________

12. Now in reverse, name these formulas with prefixes… NO 2 nitrogen dioxide CI 4 carbon tetraiodide N 2 0 dinitrogen monoxide SO 3 sulfur trioxide N 2 O 5 dinitrogen pentoxide HCl hydrogen monochloride

14. Look right now at tables K and L These are the acids and bases. We will spend about two weeks on what acid and base chemistry is all about, but today we will look at their names, see that their names and formulas are on your reference tables, say the names together, and that’s that. Also, there are 7 elements that exist NOT as atoms in their natural state. Rather they exist as pairs of atoms, diatomic elements. Mr. Smith taught this to me in the 8 th grade at Junior High School 202 in Ozone Park in Queens. I am happy to share his wisdom now. To remember these seven diatomic elements, we will call them the HONClBrIF twins H 2 O 2 N 2 Cl 2 Br 2 I 2 F 2

15. How do we decide what ratios of nonmetal atoms fit together to make compounds? Why is water H 2 O and NO OTHER hydrogen-oxygen compounds exist in any other ratio? Thinking hats on now.

16. Periodic Tables, Selected Oxidation States These numbers tell us (with some thinking) what ratios are possible, and what ratios cannot create molecules. Make this chart in your notes: H O

17. Write in all of the possible oxidation states from the Periodic Table of the Elements H O +1 -2 2:1 ratio possible -1 X: two negatives ≠ 0 The only possible combo for H and O to bond is 2:1, which spells in chemistry: H 2 O

18. Let’s determine all of the possible carbon + oxygen compounds that could form with the selected oxidation states. Remember: they must sum to zero, but the ARE NOT IONS. These atoms share electrons only. C O

19. Let’s determine all of the possible carbon + oxygen compounds that could form with the selected oxidation states. Remember: they must sum to zero, but the ARE NOT IONS. These atoms share electrons only. C O -4 -2 +2 +4

20. Let’s determine all of the possible carbon + oxygen compounds that could form with the selected oxidation states. Remember: they must sum to zero, but the ARE NOT IONS. These atoms share electrons only. There is NO WAY -4 plus -2 can ever sum to zero, this selected oxidation state for carbon is not used in any carbon – oxygen compounds. C O -4 -2 1:1 is possible +2 +4 1:2 is also CO + CO 2 are possible, nothing else is according to our periodic table.

21. Let’s do the big one: All Nitrogen + Oxygen Compounds (there are 5) N O

22. Let’s do the big one: Nitrogen and Oxygen N O -3 -2 -1 -2 +1 +2 +3 +4 +5

23. Let’s do the big one: Nitrogen and Oxygen N O -3 -2 -1 -2 +1 +2 +3 +4 +5 2:1 or N 2 O 1:1 or NO 2:3 or N 2 O 3 1:2 or NO 3 2:5 or N 2 O 5 5 Possible Compounds

24. This week… THURSDAY we will have a major review, then a celebration on naming compounds and formulas on FRIDAY Friday we start moles, bring a calculator, you’ll need it. This man is on Double Secret Probation. do you know who this is?