What do the formulas for covalent compounds tell you?
the actual amounts of each element (not just a ratio!)
What mostly bonds together in covalent bonds?
nonmetals
What is the naming system for covalent bonds?
numerical prefix then second element ends in "ide
prefix for 1-10
mono (not used for first atom being one), di, tri, tetra, penta, hexa, hepta, octa, nona, deca
What are the two categories of acids?
Binary and Oxyacids
Binary acids
hydrogen + single halogen (group 17)
How to name binary acids
hydro + halogen + -ic + acid
Oxyacids
hydrogen + oxygen-containing polyatomic ion
How to name oxyacids
-ate ions = -ic acids
-ite ions = -ous acids
How do you know the amount of hydrogen in an oxyacid?
It's the charge of the polyatomic ion
Key principles of Lewis Structures (2)
1) Must show correct number of valence electrons
2) Most atoms want 8 valence electrons
How to determine number of valence electrons?
Count however many in the highest n value
What atom never has lone pairs?
carbon
What bonds do oxygen form?
two bonds and two lone pairs
What bonds do Nitrogen form?
three bonds and one lone pair
How to determine formal charge?
Number of valence electrons (from periodic table trend) - # of long electrons - # of bonds
What is the best Lewis structure when it comes to formal charge?
The one closest to where all the formal charges are zero
How to determine best Lewis structure if the formal charge situation is the same?
Look at which atom in the ion is most interested in having a negative charge (farther right on the periodic table); the structure that has the negative formal charge on that atom is the best
resonance structures
same atoms bonded to the same atoms, but different bonding
isomers
same formula but different atoms bonded to different atoms
Forma charge lets you distinguish the best ___________ structure; it cannot compare ________________
resonance; isomers
Rules of Terse Line notation (4)
1) Ends and corners are Carbons
2) Carbons assumed to have correct number of H's
3) Explicitly draw all atoms that aren't C or H
4) Draw all H's connected to non-carbons
Take this moment to review your functional group notecards
Do it girl
How to identify an isomer?
Single bonds can be rotated, but double bonds cannot
If it can be rotated, it is NOT an isomer
If a functional group has already been claimed, can a smaller functional group within be identified?
haha nope
If you are tempted to violate the octet rule.....
make sure that all formal charges are 0
How does "expanding the octet" work? For which atoms does this only work?
the atom uses space in its d-orbitals
this only works with rows whose n is greater than or equal to 3
Is a double bond or a single shorter?
the double is shorter (tighter pull)
If there are many resonance structures, how do the bond lengths relate?
they're the same
What determines the electronic geometry of a molecule?
the number of electron groups (lone pairs and bonds)
What determines the molecular geometry of a molecule?
ONLY the amount of bonds
electronegativity
attraction in a bond between atom and the electron
polar bond; what causes it
covalent bond in which electrons are unequally shared
caused by differences in electronegativity
What is more electronegative, oxygen or hydrogen?
oxygen
How to determine if a molecule as a whole is polar by looking at bond dipoles
if they cancel out, it's nonpolar
if they don't cancel, it's polar
dipole moment; What does a small vs large number mean?
number that tells you if the compound is polar/nonpolar and how polar/non it is
small number = nonpolar; if magnitude is 1,in 10s, or larger, it's polar