What explains the result?
Water moves across cell membranes; concentrated salt outside a potato can draw water out of its cells.
LIFE SCIENCE · GRADES 4–8
Potato osmosis balance
INVESTIGATION QUESTIONHow does salt concentration change potato mass?
● ILLUSTRATIVE SCIENCE MODEL
ENGLISH CAPTIONS
Cut equal potato samples. A consistent starting size reduces variation between cups.
0.0 / 3.0 s
Where does this matter?
Osmosis explains crisping vegetables and water balance in living cells.
What should you keep in mind?
Potato variety, strip size, soak time, and blotting must match across conditions.
DEDICATED POTATO OSMOSIS LAB · GRADES 5–9
Water across
the membrane
Compare matched potato strips in three salt baths. Watch the teaching model, then measure real mass and length changes after a timed soak.
THREE-CONDITION SOAK STATIONREADY TO PREPARE
0 g salt / 100 mL
SALT BATH
CONDITION 12 g salt / 100 mL
SALT BATH
CONDITION 24 g salt / 100 mL
SALT BATH
CONDITION 3SOAK TIME
0 min
RESULTS BENCH
Change in potato mass
Illustrative percent change after the model soak
The data display stays blank until a modeled soak finishes. In a real trial, calculate percent change as ((final mass − starting mass) ÷ starting mass) × 100.
WHAT OSMOSIS MEANS: Water crosses cell membranes in response to differences in water potential. Saltier outside solution often draws water out of potato cells, while plain water can move inward. The model does not replace a balance measurement or account for potato variety, strip size, blotting or soak conditions.