Dialysis Tubing Diffusion Practical

[DoubleZo7]

Hello everyone,
I have attached a practical method.
What are some limitations to this practical?
I have come up with a few, but I am interested to see what other people think.
Also, what do you think the IV, DV and controlled variables are?
Thank-you!

[Erutepa]

Hello everyone,
I have attached a practical method.
What are some limitations to this practical?
I have come up with a few, but I am interested to see what other people think.
Also, what do you think the IV, DV and controlled variables are?
Thank-you!

Firstly, for the write-up itself, there are a few little changes you should make. You should not use personal pronouns in your discussion such as "this led me to...". Instead of this, it would be better to say "the results/observations suggest...". In addition to this, try to avoid saying things like "The starch molecules were unable to pass through the dialysis tubing..." since you cannot know this for sure - rather say "the results may be explained by..." or "these results may be due to...". These little things may seem annoying, but I think they are key to a professional sounding practical write up.
The IV is what you change. This would be the solution inside of the dialysis tubing as well as the indicators used.
The DV would be the colour changes observed in the indicators.
The major controlled variable in this experiment would likely be that of the concentration of the solution that the dialysis tube is placed within. Since distilled water was used, the concentration of the solute being tested (either starch or glucose) would have been (ideally) zero in outside the dialysis tubing initially.
No limitations come obviously to me now, but I will dwell on it and hopefully come back with some. Maybe someone else could lean in with some help.

[DoubleZo7]

Great points, thank-you
Actually isn't my report lol, just from a website that our teacher gave us. I agree that the writeup is poor.
Thanks again

[DoubleZo7]

Also, what do you think a control group would look like in this experiment if we were to improve it? Should it even have a conrol group?

[Erutepa]

Also, what do you think a control group would look like in this experiment if we were to improve it? Should it even have a conrol group?

You should add a control group whereby you put distilled water into the dialisys tube and use the same 2 indicators to check for the presence of starch and glucose.
This is important because you want to make sure that the indicator changes that you did record in your experiment are actually the result of diffusion of substance.