-What can you do with them?
add them up and they form a direction toward the more electronegative
What can the poles do?
negative pole of one may react with the positive pole of anotehr
In chemistry, what cannot you do?
break single bonds
What do arrows indicate?
the flow of two electrons
Sigma bonds are __
Pi bonds are __
sigma bond and another bond
Where can't you push electrons to?
a saturated area
In contrast to single bonds, what are double bonds?
shorter and stronger than single bonds
Where should you put the negative charge?
on the most electronegative atom
- spreading out the charge--> stabilized
- lower in energy, much more readily accessed
Explain formal charges in terms of neutral molecules.
if neutral, formal charges add up to zero
For period 2 elements, what is the deal with charges?
no double charges exist
Double charge rule
no double charges directly next to each other= too much repulsion
Explain major and minor contributors.
In resonance, they both exist. The major will be the one that most likely occurs in nature
When both resonance forms obey the octet rule, the major contributor is __
the one with the negative charge on the most electronegative atom
Condensed structural formulas
- are written without showing all the individual bonds
- atoms bonded to the central atom are listed after hte central atom
- if there are two or more identical groups, parentheses and a subscript may be used to represent them
Line angles are also called __
At the end of every line and at the intersection of any lines in line-angle structures, there is __.
a carbon atom with four bonds. Hydrogen atoms are mentally supplied to fill the valency to four
In line angle drawings, what must be shown.
atoms other than carbon and double and triple bonds
Definitions of acids and bases
- - acid: forms H30+ in water
- - base: forms OH- in water
- - acid: donates an H+
- - base: accepts an H+
- - acid: accepts an electron pair to form a new bond
- - base: donates an electron pair to form a new bond
Bronsted-Lowry acids are any species that __
donate a proton
Bronsted-Lowry bases are any species that __
accept a proton
conjugate acids and bases
- conjugate acid: when a base accepts a proton, it becomes an acid capable of returning that proton
- conjugate base: when an acid donates its proton, it becomes capable of accepting that proton back
Effect of electronegativity on pKa
As the bond to H becomes more polarized, what?
H becomes more positive and the bond is easier to break
Effect of size on pKa
As size increases, what?
- the H is more loosely held and the bond is easier to break
- a larger size also stabilizes an anion
Lewis bases are
species with available electrons that can be donated to form a new bond
Lewis acids are
species that can accept these electrons to form new bonds
Since a Lewis acid accepts electrons, it is called an __
donates electrons to a nucleus with an empty orbital (Lewis base)
accepts a pair of electrons (same as Lewis acid)
When forming a bond, __ attacks the __, so the arrow goes from __ to __.
When breaking a bond, the more __ receives the electrons.