Potato osmosis lab

Research Question:
Which salt solution caused the sailor to die?
Hypothesis:
If the sailor drank the 40% salt water solution, then would die sooner, because the high amount of salt causes more dehydration.
Variables:
Independent- Salt Solution
Dependent- Mass of Potato
Control- Tap Water
Materials:
•Tap Water (50 ml for each cup)
•Salt
•Beaker
•3 cups
•3 pieces of potato
•Scale
Procedure:
Step 1: Gather Materials.
Step 2: Weigh each potato separately on the scale and record weight in grams on table.
Step 3: Put each potato in a separate cup and add 50 ml of water to each cup, measure with beaker.
Step 4: To create the 40% salt solution add 20 grams of salt to one cup. Measure the salt using the scale.
Step 5: Add 0.2 grams of salt to the second cup. This is for the 0.4% salt water solution.
Step 6: Leave cups to sit. Check on them next class and record observations.
Sample
Initial Mass (g) Day 1
Final Mass (g) Day 2
Quantative
Data
Qualitative Data

Tonicity

Before

Hypo-
Iso-
Hyper-
40% Salt
4.01 g
3.47 g
-0.54 g
Firm
Firm

X
0.4% Salt
4.32 g
3.65 g
-0.67 g
Firm
Firm

X

Tap Water
7.5 g
6.73 g
-0.77
Firm
Soft

X

Observations:
Three potatoes were placed in three different solutions, 40% salt, 0.4% salt, and tap water. After two days the only significant change was in the potato that was in tap water. It changed from firm to soft, while the other two potatoes remained firm. There was also an awful odor that only came from the potato in the tap water.
Conclusion:
The hypothesis was correct. The 40% salt solution killed the sailor. This solution was hypertonic which causes osmosis to move the water out of the cell. The sailor then became too dehydrated and died. Salt absorbs water, which is why drinking salt water is not good for