Even though it seems fine to include the mass of the weighing boat for all the tubers, when calculating % change in mass, the denominator of the fraction will include the mass of the weighing boat as well instead of it just being the mass of the tuber, hence giving us a slightly inaccurate % change in mass. As you might say, the mass of the weighing boat might be negligible, but it would make a notable difference when dealing with such small masses. Anyway, thanks for a great video :)
Cambridge IGCSE and As/A-Level Science Thanj you. When I have time I will make more. They are unrehearsed one takes and they are far from perfect but I am glad they are useful.
Hi! Really love these videos, very helpful. May I know why a sucrose concentration is the most ideal as opposed to other non-electrolytes like mannitol?
When you get the isotonic water potential for a cell or a tissue in a solution, it would mean the external water potential is the same as the internal water potential. You get the water potential for a specific plant tissue, in this case a potato.
It isn't really the type of investigation that requires an hypothesis. You are simply finding the water potential of plant tissue. Hypothesis are testable predictions based on evidence from prior research or observations. It wouldn't be correct to randomly predict the water potential of plant tissue then test it to see if you were correct. So no hypothesis I'm afraid.
Cam S I think it's like this: Total volume of liquid in each tube is 20 cm^3. • 0M = 0 cm^3 sucrose/20 cm^3 • 0.2M = 4 cm^3 sucrose/20 cm^3 • 0.4 = 8/20 • 0.6 = 12/20 etc etc And if you're using 10 cm^3 total then it's much more straightforward (e.g. 0.2M is literally 2 cm^3 sucrose out of 10 cm^3 total liquid) And so on. Idk how you work out the individual volumes, but I'm pretty sure it has something to do with the sucrose:water volume ratios. Sorry if my reply is too late (I'm only cramming practical-related stuff now for paper 3 :/ )
C1 v1= c2 v2 this is c1 is the original concentration v1 is the 20ml = c2 is the different concentrations used and v2 is the volume needed to make it up to the 20 ml mark....late reply hope it helps
This video is great but needlessly complicated. 1ml = 1 cubic centimetre, so measurements can be done in ml instead of cubic centimetres. Also 1 decimetre is = 1000 cubic centimetres which one is 1 litre or 1000 millilitres. Why measure in decimetres cubed, does your graduated cylinder measure that way? Use 342.3 grams of sucrose per litre of water to make the sucrose solution.
It is simply the confusion that many measuring cylinders and syringes are labelled ml. Some students are confused that a ml is the same as a cm3. The videos are unrehearsed one takes. Nothing fancy but I hope a little bit helpful.
Ethan Fate independent is what you change. In this case the different concentrations of sucrose. The dependent variable is the result you measure and record. In this case the change in mass. There is no control in this investigation.
simple dilution with the formula required concentration divided concentration of given solution multiplied by the total volume of your solution you may also use serial dilution
because each potato tube has a different amount of water on its surface, so when you're weighing their masses you're only taking into account the mass of water gained or lost and not any water which might be present on its surface,.
