This is a lab report and it is due on 13th September.

The lab procedure and data is attached in here. Read through it. Then first write an abstract and second answer all of the questions in the lab procedure file. There are 3 questions in total. First question you need to make a graph in excel. Then question second is filling two tables. Question three 8 short parts to answer.

Synthesis of ethanol by fermentation of sugar
enzymes
C12H22O11
sucrose
+
H2 O
C6H12O6
+ C H O
6 12 6
glucose
fructose
CH3CH2OH
+
CO2 (unbalanced)
ethanol
(several reactions)
Today you will explore one of the oldest reactions known to humankind: the production
of ethanol from sugar catalyzed by enzymes in found in yeast. Different combinations of
sugar or starch sources (e.g. grains, grapes, potatoes) produce different alcohols (e.g.
beer, wine, rum). The alcohol content is determined by the ability of the yeast to
withstand the production of ethanol. If higher alcohol content is desired, the ethanol can
be separated from the ethanol using distillation; this technique also happens to be a
powerful purification tool in organic chemistry. Over the next two weeks, you will
conduct a fermentation, distill the ethanol, and measure the alcohol content after simple
and fractional distillations.
Background reading
Links to distillation techniques can be found at https://bit.ly/3vyff8Q
Week 1: Set up of fermentation
You will use a 125 mL filter flask (side-arm flask) as the fermentation flask. To this flask,
add 20 g of cane sugar (sucrose), 75 mL of room-temperature water (tap water is fine),
and 0.18 g of disodium hydrogen phosphate (Na 2 HPO 4 ). Stir this mixture until
everything is dissolved. Add 1.5 g of dry yeast.
Attach one end of a hose to the filter flask and the other end to a Pasteur pipet. Place
the pipet in a test tube filled half-way with saturated calcium hydroxide. The test tube
can be supported in a beaker. Stopper the flask with the one-hole stopper prepared
above. Leave the apparatus in the back of your hood until next week.
Week 2: Distillation of ethanol
Simple distillation
Add 10 g of Celite to the fermentation mixture and stir briefly until all of the Celite is wet.
Perform a vacuum filtration with a Buchner funnel (you will have to temporarily empty
the filter flask so that you can use it for filtration). Transfer the mixture to a 250 mL
round-bottomed flask. Follow the procedure outlined below.
1) Using the PowerPoint presentation and diagrams in Nichols, clamp the flask to a
simple distillation apparatus. Use a 25- or 50-mL graduated cylinder in place of the
usual receiving flask so you can monitor the volume of distillate during the
distillation. Keck clips may be used to secure the joints on either end of the
condenser (these are available on the back counter); do not use a Keck clip on the
Distillation – Page 1
distilling flask because it may melt. Be sure the thermometer is correctly positioned
as shown in your lab textbook. For proper heat transfer, adjust the heating mantle
so it just touches the bottom of the distilling flask. Attach the condenser tubing to the
condenser, hook up the lower end to the water supply, and set the upper end into
the drain. Add 1-2 boiling stones.
2) All joints should be tight, and the apparatus should be securely clamped. Have the
instructor or laboratory aide check your apparatus before beginning the distillation.
3) Turn on the condenser water to a slow stream, and set the heat controller to a
medium high setting.
4) Heat the flask until the liquid begins to boil. Adjust the controller to distill the liquid at
a rate of about 2 mL/min (2 drops every 3 seconds).
5) Record the initial temperature when the first drops of distillate fall into the graduated
cylinder and record the temperature after each 2 mL of distillate is collected.
6) Stop the distillation before the flask goes dry. You should be able to collect 20 – 25
mL of distillate.
7) Lower the heating mantle from the flask and allow the apparatus to cool.
8) Plot the temperature (y-axis) versus volume of distillate (x-axis) on the graph paper
on the back of the report form and draw the best smooth curve through the points.
DO NOT just connect the dots! You may substitute a computer-generated graph if
you wish but use a curve-fit or do it by hand to get a smooth curve; the computer’s
default setting may be to connect the dots.
9) Use a 10 mL volumetric pipet to measure out 10.00 mL of distillate. Record this
mass.
Fractional distillation
1) Add all of the distillate (including the 10 mL aliquot from above) to a 50 mL roundbottomed flask. Again, add 1-2 boiling stones.
2) Set up the fractional distillation apparatus, clamp the flask to a fractional distillation
apparatus. Pick up a Vigreux distilling column from the back counter. Again, use a
graduated cylinder in place of the usual receiving flask. Check the items in step 2
above.
3) All joints should be tight, and the apparatus should be securely clamped. Have the
instructor or laboratory aide check your apparatus before beginning the distillation.
4) Turn on the condenser water to a slow stream and set the heat controller to a high
setting.
5) Heat the flask until the liquid begins to boil. Adjust the controller to distill the liquid at
a rate of about 2 mL/min (2 drops every 3 seconds).
Distillation – Page 2
6) Continue to record the temperature after every 2 mL of distillate has been collected.
When the distilling temperature reaches 80 ºC, quickly replace the cylinder with a
small Erlenmeyer flask while you pour the contents of the graduated cylinder into a
second Erlenmeyer flask. This is your first fraction. Continue to record the
temperature of the distillate every 2 mL, until the temperature of the distillate
reaches 99 ºC.
7) Use a graduated cylinder to measure the mass and volume of the first fraction
(everything you collected before the temperature reached 80 ºC).
Distillation – Page 3
Name:___________________
Synthesis of ethanol by fermentation of sugar
1. Plot the temperature (y-axis) versus volume of distillate (x-axis) for both the simple
and the fractional distillation. The graph should clearly show individual points, as
opposed to a single line. You may connect the dots with a smooth curve if it makes it
easier to visualize.
Make sure the graphs have labeled axes, including units.
2. Fill in the tables below with data from your lab notebook and calculations (shown
below). Make sure to include units.
Distillation
Measured
Measured
mass of sample volume of
sample
Simple
Fractional
Density of fractional distillate(from table
above)
Total volume of fractional distillate (from
lab notebook)
Total mass of fractional distillate
Mass percentage of ethanol in fractional
distillate (from first table)
Mass of ethanol in fractional distillate
Theoretical yield of ethanol from
sucrose
Percent yield of ethanol from sucrose
Distillation – Page 4
Density
Mass
percentage
of ethanol
3. Show your work for the calculations above.
.
a. Density of simple distillation sample
b. Density of fractional distillation sample
c. Mass percentage of ethanol in simple distillation sample
d. Mass percentage of ethanol in fractional distillation sample
e. Total mass of fractional distillate
f. Mass of ethanol in fractional distillate
g. Theoretical yield of ethanol
h. Percent yield of ethanol
Distillation – Page 5