organic chemistry mistakes Flashcards
(19 cards)
how could GC be used to predict the number of esters in a mixture and their relative proportions
by counting the number of peaks and the relative peaks areas
why is there uncertainty about using GC alone to predict the number of esters in a mixture
some esters may have the same retention time as they might have the similar structures
How does GC separate the compounds in a mixture
by measuring their relative solubilities in the stationary phase
retention time
the time taken for each component to travel through the column
3 reasons why TMS is used as the zero reference point in NMR spectroscopy
it is chemically inert
it is non toxic
it produces a single intense peak
the region of the electromagnetic spectrum used in H NMR spectroscopy
radio waves
why is CDCl3 used as a solvent in H NMR spectroscopy
it does not have any H
so it does not show on the spectrum
which type of radiation can cause polymers to photodegrade to benefit the environment
ultraviolet radiation
when calculating atom economies, do we take into account the molar ratios?
what does this suggest
yes
suggests that if there is, for example, a 2 front of a product, then we would multiply the molar mass of that product by 2
stereoisomers
molecules with the same molecular AND structural formula but different arrangements of atoms in 3D space
an alicyclic molecule with only one carbon environment , and why
cyclohexane
because all of the carbons are surrounded 2 hydrogens each
Heterolytic fission
Breaking of a covalent bond in which one of the bonded atoms receives both electrons
Which between branched and un branched alkanes have the highest boiling point ?
Unbranched alkanes have a greater boiling point because they have a more extended shape allowing for more surface contact , and stronger intermolecular forces
Which types of bonds are broken in the reaction of alkenes with bromine
Pie and sigma bonds are both broken
Describe in terms of orbital overlap, the similarities and differences between the bonding in Kekule model of benzene and the delocalised model
Similarities
They both have a sideways overlap of p orbitals
They both have a pie bond above and below the bonding atoms
Differences
Kekule model shows 3 pie bonds
Délocaliser model has a pie ring system
How do we form aliphatic amines
React a haloalkane with excess NH3 , with ethanol as a solvent
Why do we use excess ammonia during the formation of a primary amine
To ensure that there is no leftover Haloalkane to react with the primary amine formed
Sigma bond
Overlap of orbitals directly between bonding atoms
How are carboxylic acids formed from a yo chlorides
By reacting acyl chlorides with water
