Hi. I have questions regarding the procedure about this experiment.

 

About the part where after placing a drop in each tube containg different concentration of salt solutions, the tubes were allowed to stand for 2 hours at room temp?

 

My question is why was it allowed to stand for 2 hours? Is it because it takes 2 hours for water to enter or exit the cell? are there other answers? thank you very much..

 

And why is it at room temp?

Please elaborate on what kind of experiment you talk about.

I assume that you did an experiment regarding osmotic stability of red blood cells, but it is usually better if the OP explains the question better (like spelling out RBC). Especially as it is a high school experiment with no standardized protocols.

In any case the incubation is indeed needed to for water exchange. However it does not necessarily be two hours. In the simplest case the rate is dependent on the difference of the concentration of solute inside the cell compare to the outside.