organic chem Flashcards
how many reactants in RTD of sn1 reaction
1
how many reactants in RTD of sn2 reaction
2
which sn1 or sn2 produces planar transition state
sn1
how do racemic mixtures form
nucleophile can attack from any direction
what is a racemix mix
mixture that holds equal quantities of each enantimer and do not rotate the plane of polarised light as opposite rotations of enantimers cancel each other out
which sn1 or sn2 is optically active
sn2
what forces to aldehydes have between themselves
london forces
pd to pd
what forces do aldehyde and water have between each other
london
pd to pd
and hyrdorgen bonds bc o is very electronegative
what forces do ketones have between each other
LF and PD to PD
what forces do ketones plus water have between them
LF PD to PD and HB
testing for carbonyl group
what ions involved in oxidation test
dichromate ions
what substance causes a positive test and
colour change for positive oxidation test
aldehyde
orange to green
what ions involved in fehlings test
cu2+ complex ions
what causes positive result for fehlings and colour change
aldehyde
blue to brick red
what ions in tollens test
ag+ complex ions
what causes positive test for tollens and colour change
aldehyde
colourless to silver mirror
what is used in general carbonyl test
2 4 DNPH
what is positive result from general carbonyl test and colour change
bright yellow ppt from aldehyde and ketone
how would you identify compound from bright yellow ppt
find mp and compare to known values
what intermolecular forces for carboxylic acid
LF
PD to PD
HB
are carboxylic acids soluable
yes for short chains only as non polarity of carbon chain makes them less soluble
what does tghe iodoform test, test for
aldehydes and ketones
how is iodoform test carried out
add iodine and then sodium hydroxide
what does the sodium hydroxide do in iodoform test
removes colour in solution created by iodine
what gives a positive result for iodoform test
pale yellow ppt (CH3I)
ester hydrolysis with acidic cat
what is acidic cat
h2so4
equation for acidic ester hydrolysis
ester plus water ——> carboxylic acid plus alcohol
ester hydrolysis base cat equation
ester plus NaOH —->salt plus alcohol
salt = CH3COONa
what type of reaction is acid hydrolysis
reversible
is base hydrolysis reversible or irreversible
irreversible
why is benzene so stable
outer electron from p orbital of each carbon is delocalised causing p orbitals to overlap creating a ring of electron density above and below the c atoms
properties of benzene
high mp due to high stability
low bp bc its non polar
cannot disslove in water
not very reactive due to stability
carcinogenic
suseptible to attack by electrophiles
why isnt kekule model correct
bc benzene carbon - carbon length is constant whereas kekule isnt
kekeule would easily undogo addition reactions but benzene doesnt
hydrogenation of benze is less negative than kekule model
what happens during combustion of benzene
high soot due to high carbon to hydrogen ratio
smoke flame
phenol properties
solid at rtp due to hydrogen bonds
pink crystaline solid
slightly solouble in water
dissolves in naoh to form salt as phenol is slightly acidic
what does oh group do to ring
lone pair of e actiate the pi system increasing the electron density making electrophylic attack easier
do amines accept or donate e
acceptors
amine plus water reaction
products = R - NH3+ plus OH-
reaction is reversible
what does ammonia and amides act as
ligands because tehy can donate lone pair of e to transition metal
ligand
an ion or molecule attatched to a metal by coordinate bonding
C4H9NH2 + (Cu(H20)6)2+ —–>
C4H9NH2 + (Cu(H20)6)2+ —–> (Cu(C4H9NH2)4(H20)2)2+ + 4H2O
light blue dark blue
nitrile to amine
reduction LiAlH4 dry ether dilute acid
or
Ni cat plus H2
how to get from peptide to amino acid
HCl aq
reflux
alcohol plus CA reversible or irreversible
reversible
acylchloride plus CA reversible or irreversible
irreversible
what linkage is there when amine plus CA
peptide linkage
how to make grignards
HA plus Mg —–> R- Mg- Br
in dry ether
what does grignard plus co2 make
carb acid
Ch3MgBr + CO2 —->
product and conditions
CH3COOH + Mg(OH)Br
dilute H2SO4
what does adding an aldehyde form
primary or secondary alcohol
what does adding a ketone form to grignard
tertiary alcohol
what s a homologous series
same functional group and same generalformula
nucleophile
electron pair donors
nh3 oh- cn-
electrophile
electron pair acceptors
radicals
atoms with unpaired electrons
chain isomerism
carbon skeleton arranged differently
positionla isomer
functional group changes carbon atom its attactched to
functional group isomerism
same atoms can be arranged into different functional groups
heterolytic fission
bonds break unevenly to produce two oppositely charged ions
homolytic fission
bonds break evenly to form two radicals
problem with FRS
you can get a mixture of unwanted products and structural isomers form
fracking oils from top to bottom
gases - cooking gas petrol -cars kerosene - jet fuel diesel - lorries lubricating oil - engine oil fuel oil - boats bitumen -roads
what does cracking do
produces shorter alkane and alkene
conditions for themral cracking
high pressure 70atm
and high temp 450 -700degrees
what does thermal cracking produce
high proportiona of alkenes used to make polymers
catalytic cracking conditions
zeolite cat
high temp 450 degrees
what does catalytic cracking rpoduce
high proportions of branched alkanes and aromatic hyddrocarbons
how are acid rains produced
fossil fuels contain sulfer that burns to form s02 which then dissolves to form sulphric acid in the air
NOx produced at high temps in car engines - then dissloves in air to form acid rain
what do catalytic converters do
heterogenous platinum cat
stops CO or NOx or unburnt hydrocarbons coming out and changes them into harmless gases like co2 and nitrogen
2NO + CO —> N2 + CO2
how to make ethanol
fermentation
hydration
conditions for fermentation
35 degrees and oxygen kept out to prevent oxidation
positives and negatives of fermentation
renewable slow batch production
positives and negatives of hydration
crudeoil
fast and pure
biofuels positives
renewable
release less harmful gases
carbon neutral
negatives of biofuels
batch production with low yield
carr engines need to be modified
transportation of fuels releases co2
what is sigma bond
overlapping of orbitals in space between atoms
high e density
and strong attraction between nuclei and shared e
strong
pi bond
when two p orbital overlap sideway
e density is spread out above and below nuclei
weak bond
restricts roation of molecule
