In your own words summarize the observations you made on the

In your own words, summarize the observations you made on the impact of water and 3% NaCl solution on Elodea You summary should include a comparison of the effects. When we put the NaCl on the elodea the cells shrunk and everything went towards the middle, when it was in just water everything was spread out. Refer to the following diagram, where a bag made of semi-permeable membrane is immersed into a beaker. The solutions inside the bag and inside the beaker are both NaCl solution, but the concentration in each is indicated in the diagram. For each of the 3 cases, explain, in your own words, the movement of water molecules that will take place Show the calculations you do. if any, to answer this question.

Solution

1.When we put 3% NaCl on Elodea,due to high concentration of salt,more water will diffuse out from the cell.This will result in shrinkage of the cytoplasm and pulling of cell membrane from cell wall .This is known as plasmolysis but when water will be added, water will diffuse into the cell and the cytoplasm and cell membrane will spread and take their normal shape.

2.

A. 2% means 0.02 gm/ml NaCL in bag and 3* 10^-3 gm/ml or 0.003gm/ml.Since the beaker has less concentration of NaCl, so water molecules will move from beaker to the bag.

B.1.5 % means 0.015 gm/ml NaCl in bag and 3* 10^-5 gm/ml or 0.00003 gm/ml.Since the beaker has less concentration of NaCl,so water molecules will move from beaker to the bag.

C.3% means 0.03 gm/ml NaCl in bag and 3*10 ⁴gm/ml.Since the beaker has more concentration of NaCl than bag, so water molecules will move from bag to the beaker.

(Note: The concentration of NaCl in beaker for A ,B and C as visible from the fig are taken to be 3* 10^-3 ,3* 10^-5 and3*10 ⁴ respectively).If there are any changes, the calculations can be done as above and accordingly we can find out which side has lower and which side has higher solute concentration.Water molecules will move from the lower solute concentration side to higher solute concentration side through the semi permeable membrane.)