i need hep explaining an elodea experiment?

Question

i placed 1 elodea leaf in each solution and looked at them through a microscope. the solutions were 5% sucrose, distilled water, and 4% NaCl. naturally, the chloroplasts in the sucrose solution were still spread out indicating that it was hypotonic. in the distilled water the chloroplasts were spread out indicating it was isotonic. the chloroplasts were clumped together in the NaCl solution indicating that it was hypertonic. 

question: discuss the differences between these 3 slides; propose an explanation relating to the differences between NaCl and sucrose such as molecular weight or permeability; propose an experiment to test your exaplanation and expected results if your hypothesis is correct.

ivorytowerboy · Accepted Answer

molecular weight of NaCl is 58
molecular weight of sucrose is 342

50 grams of sucrose in a liter would be 146 mM or 146 milliosmolar
40 grams of NaCl in  liter would be 689 mM or 1380 milliosmolar

Thus, the  osmolarity of the NaCl solution was about 9X greater than the sucrose. No wonder it's more hypertonic!

Note also that this statement makes no sense:

"naturally, the chloroplasts in the sucrose solution were still spread out indicating that it was hypotonic. in the distilled water the chloroplasts were spread out indicating it was isotonic."

distilled water will always be hypotonic relative to a cell.

i need hep explaining an elodea experiment?

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