organic chemistry (knight) Flashcards
What is R?
any alkyl group
What is i-Pr?
isopropyl
What is i-Bu?
isobutyl
What is s-Bu?
sec-butyl
What is t-Bu?
tert-butyl
What is Ac an abbreviation for?
acetyl group
What is Ar an abbreviation for?
an aryl group meaning any aromatic ring
What is Ph an abbreviation for?
a phenyl group
What is Bn an abbreviation for?
Benzyl
How are orbitals represented?
they are represented by a single contour within which there is a 90% chance of finding the electron
What are the three different type of p orbitals?
there are 3 degenerate p-orbitals all 90 degrees to each other
Px, Py, Pz
What are the patterns that the energies of atomic orbitals show?
- each orbital can hold a maximum of 2 electrons
- electrons are placed in orbitals from the lowest energy upwards
- electrons do not pair if there is an empty degenerate orbitals
describe the two ways that 1s orbitals overlap
the 1s orbitals can either overlap in phase and become the bonding orbital the electrons will occupy the bonding (sigma) resulting in an energy drop. Or 1s orbitals can overlap out of phase and become the antibonding orbital and this antibonding orbital if empty does not contribute to the energy
Why doesn’t helium form He2?
the four electrons in helium would fully occupy both the bonding orbital and the antibonding orbital resulting in an overall energy increase so it is energetically unfavorable
describe a sigma orbital and how they are formed.
sigma orbitals are cylindrically symmetrical
a sigma bond can be formed by an overlap of 2 s orbitals or by one side on p and one s in the same phase to make the bonding orbital or a p orbital side on and an s orbital in different phases to make the antibonding orbital. this is the same logic with 2 p orbitals end on
how do u produce pi orbitals
side on overlap of p orbitals in phase will produce the bonding pi orbital and out of phase overlap of 2 end on p orbitals will produce the antibonding pi orbitals
describe sp3 hybridization
mixing 1 s orbital and 3 p orbitals this we generate 4 hybrid orbitals which point to the corners of a tetrahedral in order to be as far apart as possible this means there are no remaining p orbitals and it can for 4 sigma bonds
describe sp2 hybridization
mixing one s orbital and 2 p orbitals will generate 3 identical sp2 hybrid orbitals which will be trigonal planar structure in order to be as far apart as possible there will be 1 remaining p orbital. and these can for 3 sigma bonds and one pi bond
describe sp hybridisation
when one s orbital and one p will generate 2 hybrid orbitals which will take a linear structure containing 2 remaining p orbitals which can for 2 sigma bonds and 2 pi bonds
draw an n-propyl group
see one note
draw an iso-propyl group
see one note
draw an n-butyl group
see one note
draw an iso-butyl group
see one note
draw a sec- butyl group
see one note
draw a tert-butyl group
see one note
draw formic acid structure
methanoic acid see one note
draw formaldehyde
methanal see one note
draw acetic acid
ethanoic acid see one note
draw acetaldehyde
ethanal see one note
draw acetyl chloride
draw ethyl acetate
draw benzene
draw toluene
draw pyridine
draw phenol
draw acetone
draw diethyl ether
draw THF
what does THF stand for
tetrahydrofuran
draw DMF
what does DMF
dimethylformamide
draw DMSO
what does DMSO stand for
dimethylsulfoxide
what is an orbital
Orbitals describes energy and distribution of an electron, orbitals are represented by a single contour where there is a 90% chance of finding the electron
what are the 3 degenerate p orbitals of equal energy
Px, Py, Pz
all at 90 degrees to each other
What brings molecules together
- Cations and anions
- Ions and dipoles
- Dipoles and dipoles
how can reactions still happen if there are no charges or dipoles
Reactions involve changes in the bonding: bonds are made and broken, and this is caused by a flow of electrons
One reactant donates electrons the nucleophile and the other reactant accepts electrons the electrophile
Electrons reside in orbitals
how do we form molecular orbitals
We should use filled-empty orbital overlap and the most favourable is between the nucleophile HOMO and the electrophile LUMO
define HOMO
highest occupied molecular orbitals
define LUMO
lowest unoccupied molecular orbitals
what is the pKa of HI
-10
what is the pKa of HCl
-7
what is the pKa of H2SO4
-3
what is the pKa of H3O+
-2
what is the pKa of HSO4-
2
what is the pKa of acetic acid
5
what is the pKa of H2S
7
what is the pKa of NH4+
9
what is the pKa of a phenol
10
what is the pKa of MeOH
15
what is the pKa of H20
15
what is the pKa of propanone
20
what is the pKa of alkyne
25
what is the pKa of NH3
33
what is the pKa of CH4
48
what factors affect pKa and acidity
1) Weak A-H bonds lead to stronger acid
2) Stability of the conjugate base A- due to the charge being on an electronegative atoms
3) Delocalization of the - charge makes A- more stable HA more acidic
4) Inductive effects can stabilize A- and increase the acidity of HA
5)Hybridisation can affect pKA - the more s character the more stable s
