Question

a student wants to model the net movement of water out of a cell using a semi - permeable bag, water, a large beaker, and salt. which setup could he use to model the net movement of water out of a cell? responses
a. place a bag containing a 30% salt solution into a beaker containing a 10% salt solution
b. place a bag containing a 30% salt solution into a beaker containing a 20% salt solution
c. place a bag containing a 10% salt solution into a beaker containing a 10% salt solution
d. place a bag containing a 20% salt solution into a beaker containing a 40% salt solution

Explanation:

To model water moving out of a cell, the cell (bag) should be in a hypertonic solution (higher solute outside, so water leaves). Let's analyze each option:

• Option A: Bag (30% salt) has higher solute than beaker (10% salt). Water would move into the bag (hypotonic outside), not out. Eliminate A.
• Option B: Bag (30% salt) vs beaker (20% salt). Bag has higher solute. Water moves into the bag. Eliminate B.
• Option C: Both 10% salt. Isotonic, no net water movement. Eliminate C.
• Option D: Bag (20% salt) vs beaker (40% salt). Beaker has higher solute (hypertonic outside). Water moves out of the bag (cell) into the beaker. This matches the requirement.

Answer:

D. Place a bag containing a 20% salt solution into a beaker containing a 40% salt solution