Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
49 Cards in this Set
- Front
- Back
|
What is the s character and p character percentage for an:
SP SP2 SP3 |
SP = 50 % for each
SP2 = 33% s and 67% for p SP3 = 25% s and 75% for p |
|
|
What is the molecular geometry:
SP SP2 SP3 |
SP = is linear and angle is 180
SP2 = is trigonal planar and angle is 120 SP3= is tetrahedral and angle is 109.5 |
|
|
How do you determine the degree of unsaturation and what does unsaturated mean
|
Unsaturated means one double bond or a ring and the formula for degree of unsaturation is:
((2n + 2)-X/2) X is for hydrogens and halogens. If Nitrogen then add one carbon and add one hydrogen |
|
|
Describe what a degree of unsaturation of 2 means
|
This could mean:
2 double bonds, 2 rings 1 ring and 1 double bond |
|
|
What is the trend if you have a shorter bond length, when comparing BDE and number of bonds
|
The BDE will be higher and the number of bonds will also be higher
|
|
|
What does BDE mean and how should you use it to compare different bonds in comparison to similar bonds
|
BDE is the energy required for homolytically cleave and should ONLY be used for similar bonds
|
|
|
What are the characteristics of a regiosmer and what are the other names for this isomer? Also are they easy to separate....
|
These are called constitutional isomers, regiosomers or structural isomers. They are the same formula, just connected differently. Yes they are easy to separate.
|
|
|
What are some characteristics of an conformational isomer?
|
Can’t separate at room temperature
Same atomic connectivity but differ by rotation around sigma bond |
|
|
What are the four rules for giving absolute stereocenter configuration
|
Put the priority on the atom with the highest atomic number (then atomic weight)
If dashed line is not 4 then switch two numbers so it is. Only label 1-3 If followed step 2 then switch R and S |
|
|
What do entiomers share in common, concerning physical properties
|
They share almost all chemical properties
|
|
|
What makes an entiomer
|
They have at least one chiral center and all the chiral centers are different
|
|
|
What property is different with enantiomers
|
The optical rotation is the same magnitude but opposite direction
|
|
|
Is a racemic mixture of enantiomers optically active and is a meso compound optically active
|
No
|
|
|
What is used to separate enantiomers
|
Resolution
|
|
|
What is used to separate diasteromers
|
Fractional Distilation
|
|
|
What is used to separate constituitional isomers
|
Simple Distilation
|
|
|
What isomer is this based on these characteristics:
o Must have two chiral centers o Not all chiral centers are opposite o No way to determine specific rotation o They also have different chemical properties |
Diasteromers
|
|
|
What makes an epimer
|
An epimer is a fisher projection for a sugar and differs at one sterocenter
|
|
|
How do you specify the D or L in an epimer
|
o The d or l is being specified by the highest number chiral center in the fisher projection
If hydroxyl group on the right it is D |
|
|
What is an anomer
|
It is a cyclized ring of epimer
|
|
|
Where do anomers differ
|
o They differ at the anomeric carbon which is C-1
|
|
|
What are some characteristics of a meso compound?
|
o Can’t have meso compounds
o Optically inactive o Have even number of chiral compounds o Have to look at the mirror image |
|
|
What is needed to have conjugation/resonance
|
You need to have three or more sp/sp2 in a row
|
|
|
What makes the best resonance structure, write in order of priortity
|
Fill Octet rule
Minimize the separation of charge Having the negative charge on electronegative |
|
|
What happens if you have an lone pair atom concerning resonance
|
If atoms with lone pairs is adjacent to sp2 then it is sp2
|
|
|
When does melting point/boiling increase
|
Longer chain and increase IMF
|
|
|
When does Boiling/Melting decrease
|
Add more chains
|
|
|
How many hydrocarbons in water are considered soluble
|
5 or less
|
|
|
What are electron donating
|
Atoms which are not electronegative
|
|
|
What are electron withdrawing
|
Atoms which are highly electronegative
|
|
|
What usually stablizes electron rich, anion
|
Electron withdrawing
|
|
|
What stabilizes electron poor
|
Electron donating
|
|
|
What are alkyl substituents always on MCAT, elctron donating or withdrawing
|
Donating
|
|
|
What is the most favorable rings in order
|
6 >5 > 7
|
|
|
When drawing chair conformations, what corresponds to up and with the chair
|
If dashed lines go up
If solid go with chair |
|
|
What steriosomer is does this description fit?
They are similar in all physical and chemical but differ in optical rotaation All chiral centers are opposite If two together their is no optical activity They are non-superimposable |
Enantiomers
|
|
|
What process separates enantiomers
|
Resolution
|
|
|
What represents this steriosomer?
Must have all chiral centers One of the chiral centers aren't opposte |
Diasteromer
|
|
|
How do you separate a diasteromer
|
Fractional Distillation
|
|
|
When classifying an epimer, how do you classify?
|
The D or L is specified based on the highest chiral center number in the fisher projection
|
|
|
When an fisher has one of its chiral center that is opposite from the other pair, what is this called?
|
Epimer
|
|
|
In a geometric isomer, E,Z, how do you rank the sudes
|
Use the atomic weight
|
|
|
In sugars, what is the name of the carbon that makes the chain an epimer?
|
An epimeric carbon
|
|
|
If you increase branching, what happens to mp and bp
|
You will decrease
|
|
|
You increase length chain and IMF, what happens to mp and bp
|
You will increase
|
|
|
If you have a meso compound, how can you tell how many steroisomer?
|
2*n-1= n is numbr of chiral centers
|
|
|
Are meso compounds optically active
|
No
|
|
|
Are alkyl subuinits always donating or withdrawing
|
Donanting
|
|
|
To be aromatic what must a compound be
|
Must be conjugated
Must be in a ring system Must follow the 4n+2 rule |
