experiment 3 - biosynthesis and distillation of ethanol

Draw ethanol

What’s the overalll reaction for fermentation to ethanol

What is ethanol best known as (not in lab manual)

A type of alcohol in beverages, solvent for thermometers and as fuel

What are the three fold representations of matter (not on lab manual)

1. Macroscopic

2. Microscopic

3. Symbolic level

In terms of the three folds of matter representation describe ethanol on all levels (not in lab manual)

1. Macro - bottle of alcohol

2. Micro - distillation process of ethanol and water

3. Symbolic - using chemical symbols, formulas and equations to describe the reaction

What occurs when you ferment sugar

Sucrose converts to ethanol and carbon dioxide, carried out by yeast and tap water

What is fermentation to ethanol

Series of reactions, each requiring an enzyme as a catalyst, certain ions and co catalysts

Distillation

Process used for the separation of components of a liquid mixture, exploiting difference in boiling points of the components

• boiling liquid and condensing vapours at different temperatures results in seperation of liquids

• yields one theoretical plate

2 differences between distillation of a pure vs mixture liquid

• pure liquid has constant boiling temperatures while mixture has constantly rising temperature

• Pure liquid distillation also gives pure distillate where as mixture has changing composition of the distillate

Fractional distillation

• vapour has to rise through a fractioning column before entering the distillation head

• The fractionating column has a large internal surface area for the recondensation and redistillation of vapour

• Yields a seperation of several theoretical plates

What’s the standard yeast viable that should be resulted from the experiment

12-14%

Formula for % atom economy (AE)

AE% = ( molar mass of product / molar mass of all reactant) 100

Formula for RME

1. Based on mass

RME = (actual mass of desired product / total mass of reactants) 100

2. Based on yield and atom economy

RME = atom economy x percent yield / 100

Steps to calculating mols of ethanol and yeast viable

1. Convert sugar mass → mols

2. Mols sugar x 4/1 = mols ethanol (mol ratio)

3. Mols ethanol → grams of ethanol

4. Yeast viable = (grams of ethanol / vol h2O (mL) ) x 100

The maximum ethanol production possible during fermentation of 55g of sucrose in 250mL of water is…

29.6g

The maximum ethanol production possible during the fermentation of 75 g of sucrose in 250 ml of water is:

30.0g

When making a graph for boiling points, density and ethanol content what is on each axis

X - %ethanol

Y left side - boiling point celcius

Y right side - density g/ml

A 210 ml sample of the original ferment was collected which had a density of 0.979 g/ml. The ethanol content (in grams) of this sample is:

29.4g

A 38.0 ml sample of the simple distillate was collected which had a density of 0.969 g/ml. The ethanol content (in grams) in the simple distillate is:

7.98g

A 6.0 ml sample of the second fraction of fractional distillation was collected which had a density of 0.960 g/ml. The ethanol content (in grams) in the fractional distillate sample is:

1.62g

When is ethanol content highest

First fraction collected from fractional distillation

According to the diagram, reading the hygrometer what’re the density indicated at position a, b and c

A- 0.813g/ml

B- 0.830g/ml

C-0.879g/ml

Using the information, determine ethanol content in % and in g for each fraction collected. Assuming starting amount of 55g of sucrose, calculate yield and RME for ethanol in each of the ferment, simple distillate and combined fractional distillates. Also comment on ethanol content as a function of the distillation procedures employed

Idk… let’s figure it out tgt…