ERROR2 an experiment has been performed below. what can be the sources of error in this experiment and how can you devel
Posted: Sun May 22, 2022 5:01 pm
ERROR2
an experiment has been performed below. what can be the sources
of error in this experiment and how can you develop the
experiment to get a better yield, for example. The
yield is written below.
alcohol oxidation= 20 mmol
flowchart alcohol oxidation
transfer to a 50 ml erlenmeyer flask of 2,1 ml of
cyclohexanol, 10ml ethyl acetate and 1,6 ml of pyridine by
pipette.
⇩
add a stir bar and stir the mixture until
homogeneous.
⇩
mix 5ml ethyl acetate and 1,2g TCCA and transfer into a
100 mL beaker, then stir with a glass stirring until it dissolved
(takes a few minutes)
⇩
transfer the mixture of the beaker to a separatory
funnel and set up as a dropping funnel for the erlenmeyer
flask
⇩
drip the contents of the separatory funnel into the
erlenmeyer flask over a period of 5-10 min (the erlenmeyer flask
will be hot make sure it does not get hotter than 40
degrees)
⇩
stir the solution an additional 20 minutes
⇩
run a TLC of the solution by using as a eluent 30% ethyl
acetate and 70% hexane (If the alcohol is not detected by TLC glass
wool filter the solution and rinse the product that is stuck in the
filter funnel with 3-5 ml of ethyl acetate.)
⇩
test the solution for excess TCCA by placing a drop of
the reaction mixture on a wet starch-iodine test drip. If you get a
color its positive means that you will add 3-5 ml saturated sodium
bisulfite and shake vigorously. If you don't get any color or light
yellow it means negative so continue with next
step
⇩
Wash three times the organic layer with 10mL 1 M HCl, 10
mL 5% sodium bicarbonate (NaHCO₃) and 5 mL saturated NaCl.
Separate the two different layers and discord the lower aqueous
layer after every wash.
⇩
transfer the organic layer to a 50 mL Erlenmeyer flask
and dry it with MgSO₄
⇩
glass wool filter the solution
⇩
evaporate with rotary evaporator
⇩
record the yield and run IR-spectra
Theoretical yield: 0,02x100,168g/mol= 2,00g
maximum
Weight of the rounded bottom flask= 78,65g
weight of the rounded bottom flask + products solution=
80,51g
weight of the products solution=
80,51g-78,65g=1,86g
Yield= 1,86g/2gx100= 93%.
an experiment has been performed below. what can be the sources
of error in this experiment and how can you develop the
experiment to get a better yield, for example. The
yield is written below.
alcohol oxidation= 20 mmol
flowchart alcohol oxidation
transfer to a 50 ml erlenmeyer flask of 2,1 ml of
cyclohexanol, 10ml ethyl acetate and 1,6 ml of pyridine by
pipette.
⇩
add a stir bar and stir the mixture until
homogeneous.
⇩
mix 5ml ethyl acetate and 1,2g TCCA and transfer into a
100 mL beaker, then stir with a glass stirring until it dissolved
(takes a few minutes)
⇩
transfer the mixture of the beaker to a separatory
funnel and set up as a dropping funnel for the erlenmeyer
flask
⇩
drip the contents of the separatory funnel into the
erlenmeyer flask over a period of 5-10 min (the erlenmeyer flask
will be hot make sure it does not get hotter than 40
degrees)
⇩
stir the solution an additional 20 minutes
⇩
run a TLC of the solution by using as a eluent 30% ethyl
acetate and 70% hexane (If the alcohol is not detected by TLC glass
wool filter the solution and rinse the product that is stuck in the
filter funnel with 3-5 ml of ethyl acetate.)
⇩
test the solution for excess TCCA by placing a drop of
the reaction mixture on a wet starch-iodine test drip. If you get a
color its positive means that you will add 3-5 ml saturated sodium
bisulfite and shake vigorously. If you don't get any color or light
yellow it means negative so continue with next
step
⇩
Wash three times the organic layer with 10mL 1 M HCl, 10
mL 5% sodium bicarbonate (NaHCO₃) and 5 mL saturated NaCl.
Separate the two different layers and discord the lower aqueous
layer after every wash.
⇩
transfer the organic layer to a 50 mL Erlenmeyer flask
and dry it with MgSO₄
⇩
glass wool filter the solution
⇩
evaporate with rotary evaporator
⇩
record the yield and run IR-spectra
Theoretical yield: 0,02x100,168g/mol= 2,00g
maximum
Weight of the rounded bottom flask= 78,65g
weight of the rounded bottom flask + products solution=
80,51g
weight of the products solution=
80,51g-78,65g=1,86g
Yield= 1,86g/2gx100= 93%.