Why do you have to rinse dialysis bag with water?
What was the purpose of rinsing the dialysis bag before placing it in the beaker? To rinse off any starch and glucose that spilled on the dialysis bag so that the water in beaker remains as distilled water at the beginning of the experiment3. To make sure there wasn’t any glucose in the distilled water. 4.
Can water pass through dialysis tubing?
Discussion. The dialysis tubing is a semipermeable membrane. Water molecules can pass through the membrane.
What would happen if a dialysis bag is filled with distilled water and then placed in a sucrose solution?
A dialysis bag is filled with distilled water and then placed in a sucrose solution. The bag’s initial mass is 20g, and its final mass is 18g. The sucrose solution in the beaker would have been hypertonic to the distilled water in the bag.
Why is it necessary to include both positive and negative controls in the experiment with dialysis tubing?
The purpose of the positive control is to prove that the experiment can produce a positive result, such as a change in the dependent variable. Thee negative control is supposed to result in a lack of change in the dependent variable.
What would happen to the mass of each bag in this experiment if all the bags were placed in a solution of distilled water?
The mass of each bag would stay the same because both substances have sucrose in it. They would diffuse until they reached equilibrium, Since the bags were placed in distilled water, the water diffused into the bag making the mass increase.
Is diffusion through a semipermeable membrane?
Osmosis is in fact a kind of diffusion, and it’s the nature of the membrane that makes the difference between diffusion and osmosis. If we now change the membrane separating the two compartments so that only water can pass through it, then the movement of glucose will be stopped.
Why did we use sucrose instead of glucose in this experiment?
Sucrose is formed in the cytosol of photosynthesizing cells from fructose and glucose and is then transported to other parts of the plant. Sucrose contains more energy than a monosaccharide, so it is more energy efficient, both in transport as in storage. Secondly, sucrose is a so called non-reducing sugar.
Is maltose reducing sugar?
Maltose undergoes mutarotation at its hemiacetal anomeric center. Recall that the process occurs via an open-chain structure containing an aldehyde. The free aldehyde formed by ring opening can react with Fehling’s solution, so maltose is a reducing sugar.
What color does Benedict’s solution turn in the presence of glucose?
In lab, we used Benedict’s reagent to test for one particular reducing sugar: glucose. Benedict’s reagent starts out aqua-blue. As it is heated in the presence of reducing sugars, it turns yellow to orange. The “hotter” the final color of the reagent, the higher the concentration of reducing sugar.
What is the relationship between the change in mass and molarity of sucrose?
As the sucrose molarity in each bag increases, a greater change in mass occurs. More water diffuses into the bag with increasing molarity. THe higher the molarity, the higher the % change in mass.
What would happen to the mass of each bag in this experiment if all the bags were placed in 0.4 M sucrose solution instead of distilled water?
Predict what would happen to the mass of each bag in this experiment if all the bags were placed in a 0.4M sucrose solution instead of distilled water. With the 0.2M bag, the water would move out. With the 0.4M bag, there will be no net movement of water because the solutions reach dynamic equilibrium.
Why did you compare the percentage change in mass rather than simply the change in mass of each chip?
3. Why did you calculate the percent change in mass rather than simply using the change in mass? Answer: The difference in mass does not deal with the proportional aspect of the solutions, making the results less accurate. This would be the sucrose molarity in which the mass of the potato core does not change.
Why is percentage change more accurate?
Usually you are going to be working with larger datasets and quantities, so it is more important to use the percentage change method because as you can see the percentage change method gives a more precise description as to how the data has changed over a period of time.
How do you calculate the change in mass?
Mass Difference= Final Mass- Initial Mass To find the “Percent Change in Mass,” divide the “Mass Difference” by the “Initial Mass.”
Why do we use percent change in mass?
The percent change in mass shows what proportion of a substance’s mass has changed over time. For instance, if one-fourth of a rock’s mass is worn away over a year, that rock’s mass has a change of 25 percent.
Is 400 the same as 4 times?
Definition – What is a percentage? A percentage is a number expressed as a fraction of 100. If a number is 400%, then it is 4 times, the same as 4.