With the four different equations, we can calculate the different masses of the released ethanol and carbon dioxide.
On the occasion of the equations of the fermentation of the four sugars we can almost conclude that the biggest mass of ethanol and carbon dioxide will be produced by cane sugar or malt sugar. Out of the proportion between the sugars and the equation products we can see that glucose and fruit sugar fits twice in cane sugar and malt sugar. These two sugars have a proportion of 1:4 with their equation products. But before we can make our complete hypothesis, we also need to know the different kind of properties of the two different kind of sugars;
On the internet we discovered that every organism is able to break off malt sugar. And yeast is a Fungi, so it counts as an organism. Cane sugar is sugar made from cane but doesn’t really carry an extraordinary property.
So out of this information we can form our hypothesis; malt sugar will release the biggest mass of ethanol and carbon dioxide.
Experimental procedure and approach
First of all we needed to calculate how much we needed of the four different sugars. We took 0,1 mol of fruit sugar and glucose and we calculated the mass of both of the sugars by multiplying the mol with the molar mass (180,2 * 0,1 = 18,02 gram fruit sugar and glucose). For cane sugar and malt sugar we used 0,05 mol for each, that’s because the molar proportion of C6H12O6 and C12H22O11. So by multiplying the mol cane sugar and malt sugar with the molar mass we can calculate the mass: 342,3 * 0,05 = 17,12 gram cane sugar and malt sugar. But malt sugar is only available in syrupy fluid, which contains 74 gram malt sugar in 100 gram syrupy fluid.
Then we weighed the needed quantity of the sugars. So when we put the right mass sugar in the conic flask, we filled the conic flask with 100 mL demiwater, which we measured earlier before with a measuring cylinder. We used a measuring cylinder because it is the most accurate way of measuring. Now the solution was made, we needed the yeast to complete the experimental solution. We took for each conic flask 1,5 gram yeast and we added the yeast to the solution. Then we weighed the conic flasks with the sugar-solution and the yeast.
Apart from the fermentation experiment, we weighed an extra conic flask, and filled it with also 100 mL (weighed) demiwater to calculate the evaporated H2O. Because in the sugar-solutions the added demiwater can also be evaporated.
This whole trial is done twice because we do a duplicate determination to be sure the data is reliable.
After we make the solutions, we put the conic flasks by a temperature of 25 degrees (298 K) for about two days. We did this because we wanted to check Slaa et al.’s data. When we came back after two days we found out their data is reliable because the yeast cells didn’t ferment at all.
After we found out, we put all the conic flasks in a warmth bath of 37 degrees for three days.
At last, when we get all the conic flasks out of the warmth bath, we weighed them again.
The extra conic flasks we used during the whole experiment showed us after the whole process how much demiwater is evaporated during the whole experiment. We can calculate this by subtract the ‘new’ mass from the ‘old’ mass.
Results
Three days after the morning we put the conic flasks in the warmth bath, we came back to weigh all the solutions. The smell was a very heavy smell of alcohol, some sort of strong beer-scent.
Table 1, 2 and 3 present - in duplicate - the mass of the solution before the beginning of the experiment, the values of the solutions after they were placed at 25 degrees and the values of the solutions when they got out of the bath.
Table 1 Before bath
Table 2 25 degrees (298 K)
Table 3 37 degrees (310 K)
Table 4 and 5 (beside) show how much water is evaporated and how much ethanol is produced by the fermentation of measurement 1 and measurement 2.
Figure 1 (below) shows in duplicate the bar plot of the ethanol which is released by the different sugars
Table 4
Measurement 1
Table 5
Measurement 2
Data analysis
The mass of the released ethanol of one measurement is calculated by the following formulas:
mass demiwater before warmth bath – mass demiwater after water bath = evaporated water
mass solution before warmth bath – mass solution after warmth bath = weight loss solution
weight loss solution – evaporated water = produced ethanol
As an example we use the values of the fruit sugar from measurement 1 to show what we exactly did:
225,86 – 225,35 = 0,51 gram evaporated water
255,66 – 244,05 = 11,61 gram weight loss of the solution
11,61 – 0,51 = 11,1 gram produced ethanol
Discussion and conclusion
It’s obvious that the biggest mass of ethanol is produced by the fermentation of glucose as you can see in the bar plot of the released ethanol. As you can see in table 2, glucose performed the biggest loss of weight during the experiment. So during the fermentation, glucose was able to produce a lot of ethanol. The average weight of the produced ethanol is 12,39 gram. On the occasion of this conclusion, we can say that our hypothesis is wrong. We thought that malt sugar would release the most ethanol with it’s fermentation. But we didn’t notice that it’s possible that the syrupy malt sugar contains components with inhibitory function.
Evaluation
The experiment expired very well, we kept every conic flasks with the solution under the same circumstances during the whole experiment. So the variables were kept the same the whole time. Only the kind of sugar was changed; out independent variable to inquire if the kind of sugar is determinative to the mass of the released ethanol. Everything was easy to retrieve and kept at a safe place. So the set up was suitable enough to achieve the answer to our inquiry question.
An improvement can be that we heat the sugars to their boiling point, and liquefy the sugar and the water under a
high temperature; the boiling point. The boiling point is different for every sugar so the sugar will be heated to it’s own boiling point to make the solution with water. There is a chance that the released ethanol will be different from the released ethanol when the sugar isn’t warmed. So that could be the customized independent variable.
Bibliography
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