A student fills four sections of dialysis tubing with the following solutions and ties them off: (W) distilled water, (X) 10% sucrose, (Y) 30% sucrose, (Z) 50% sucrose. Each bag is weighed, immersed in a beaker of distilled water, and reweighed after 30 minutes. The dialysis membrane is permeable to water but not to sucrose.
Which bag is predicted to gain the most mass?
- A
X (10% sucrose)
- B
W (distilled water)
- Ccheck_circle
Z (50% sucrose)
- D
All bags will gain equal mass
Explanation
Water moves down its concentration gradient from the hypotonic external (distilled water) into the most hypertonic interior (50% sucrose, bag Z). Bag W is isotonic with its environment and will not gain mass.