organic chem 1-2 Flashcards
what does n represent when writing the IUPAC name for example n-propyl?
n- REPRESENTS that it is non branched and linear
what is it called when a benzene ring has Ph attached to it?
it is not benzene it is Phenyl (sometimes Phenyl doesn’t need to be drawn- the ring of it- it can just be represented as Ph)
what are the energy levels in order?
1s2 2s2 2p6 3s2 3p6 3d10 4s2
how can different types of orbitals be differentiated?
their shape and symmetries
what are the wave properties of electrons?
standing wave vibrates in fixed location. a standing wave appears to be vibrating vertically (up and down) without travelling side to side (horizontally)
amplitude can be positive or negative. what is the amplitude of a wave?
the height (shows how much energy the wave has)
what is the node of a wave?
the point where the amplitude is zero (the line) and the point doesn’t move
what does an s orbital look like ?
spherically symmetric around the nucleus, no phase change
when drawing energy levels how do you draw them?
fill up each box individually first with one electron then start paring them, without opposite spins, arrows go through the line
what does the second electron shell look like
another shell around the spherical node (where there is no electron density)
what is the node in terms of electron shells?
region of space around the nucleus where the probability of finding an electron is ZERO
WHAT DO p orbitals look like?
2 oval shapes opposite one another
how many p orbitals are there
3 p orbitals. (2p6)
what does the distance from the node of the p orbital to the end of the oval mean?
the distance it is from the nucleus
what does the height of the p-orbital wave mean
the electron density
what are valence electrons?
electrons on the outermost shell of the atom
what does aufbau principle state?
fill the lowest energy orbitals first
what does Hund’s rule state?
when there are 2 or more orbitals of the same energy, electrons will go into different orbitals rather than pairing up in the same orbital.
what holds ionic bonded atoms together?
electrostatic attraction
what does non-polar mean in covalent bonds?
electrons are shared evenly in the bond
when there a polar covalent bond what does this mean?
electrons are not shared evenly between the atoms, where each atom has a different electronegativity. (more of a pull on the electron towards itself)
what is electron density?
the relative amount of negative charge that is located at each point
what do lone pairs determine?
the reactivity
which c-c bond length is the longest ?
single/sigma c-c bond have larger bond length as only 2 electrons pull the atoms together in the bond
which c-c bond length is the shortest?
triples bond as there are 6 electrons and a stronger pull towards each other- decreasing the bond length
how do you workout dipole moment?
amount of electrical charge x bond length
what is a EPM?
electrostatic potential map is a representation where the electrostatic potential at the molecular surface is indicated by colours so its easy to visualise the distribution of charge in a molecule. (red is negative and blue is positive)
what is the trend for electronegativity in the periodic table
electronegativity in creases as you go across the table
nitrogen, oxygen, fluorine, sulfur, chlorine, bromine, iodine
how can it be predicted whether a bond will be polar?
electro negativities can be used to predict this
in bond dipole moments what does the arrow represent?
arrow: bond dipole created and the direction the electrons pull towards-> delta negative one (more electronegative pull)
what are dipole moments due to ?
difference in electronegativity and amount of charge and stance of separation (measure in debyes D)
NH2 (AMINE), OH (ALCOHOL), Cl, N+-CL-
order these groups attached to alkanes in order of increasing polarity
NH2 (AMINE),
OH (ALCOHOL),
Cl,
N+-CL-
if two of the same atoms or molecule was joined together in a bond would it be polar or non polar
E.G:
H2
CH3-CH3
NON-POLAR SIMILAR ELECTROGNETIVITY
TRUE OR FALSE:
Electronegativity differences
of less than ~0.4 result in nonpolar covalent bonds,
Differences up to 1.9 indicate increasingly polar
covalent bonds, and differences of 2 or more
indicate ionic bonds.
true
what is the polarity of a c-h bond
non-polar
what does a correct dipole orientation look like?
arrow above bonding pointing from left to right unless its a 3d shape
how does a molecule with polar covalent bonds have no net polarity?
their symmetrical shapes cause individual bond polarities to cancel each other out
is bezene rings polar or non polar
non polar
what happens to toluene in water?
toluene floats in water as it is less dense than water
what is the equation for working out the formal charge?
Formal Charge= number valence electrons - (e- in lone pairs + number of bonds)
what does lipophilic mean?
the ability of a chemical compound to dissolve in fats, oils, lipids and non polar solvents such as hexane or toluene.
what are lipophilic features?
like benzene, ch3, c-c
non-polar
what are hydrophilic properties?
OH, N
polar
what are the two linear combination of atomic orbitals?
bond formation, hybridisation
what is bond formation?
bonds between different atoms
what is hybridisation?
bonding on the same atom
what does IN PHASE mean in wave interactions?
two waves coincide with peaks and troughs matching
what happens to waves that are in phase
they add together and aptitude increases
what happens to waves that are out of phase?
the waves out of phase cancel out and cause a destructive overlap.
what happens when 2 1s orbitals of two hydrogen atoms overlap in phase with each other?
formation of σ-bonding MO (sigma)
what happens when 2 1s orbitals combine out of phase?
generates anti bonding molecular orbital.
what happens when 2 p-orbitals overlap?
forms a bonding orbital and anti bonding orbital
what does a bonding orbital look like of p orbitals
one bit positive orbital in the centre with one negatively charged on each side, with a nucleus between them
what does a sigma anti bonding orbital look like from a destructive overlap?
node split in the centre and on each side is a positive and negative orbital with a nucleus in the centre. the node has one side with a positive orbital and other side with a negative
what does the overlap of s and p orbitals give?
bonding mo and anti bonding mo
what does a sigma bonding mo look like between a s and p orbital ?
p orbital with negative and positive ovals with nucleus in the middle is bonded to a s orbital with a positive charge
it creates the same p orbital but the positive charged side of the p orbital is doubled due to the positive s orbital side joining to it
what does a sigma ANTIbonding mo look like between a s and p orbital ?
p orbital with negative and positive ovals with nucleus in the middle is bonded to a s orbital with a negative charge
p orbital with a node in the next to it separating it from a negative s orbital on the other side of the nose
what does the sideway overlap of 2 p orbitals lead to?
pi bonding mo and a pi anti bonding mo
which is strong a pi bond or sigma bond?
sigma bond
what does a double bond (2 pairs of electrons shared) consist of?
sigma bond, pi bond
what does a triple bond consist of?
1 sigma bond
and
2 pi bond
is bonding or anti bonding MO (MOLECULAR ORBITAL) HIGHER in energy compared to the original atomic orbital which wasn’t bonded?
anti bonding mo
