Question

1. make a claim about the water potential of the potato. provide evidence and reasoning to support your claim.

claim

• the water potential of the potato is equal to the 0.2 m nacl solution.

evidence
b
reasoning

• a 0.2 m nacl solution is hypertonic with the potato cells.
• a 0.2 m nacl solution is isotonic with the potato cells.
• a 0.2 m nacl solution is hypotonic with the potato cells.

graph 1 title
% change in mass (%)
select all points
% change in mass
% change in mass linear fit

Explanation:

1. Claim: Isotonic solutions have equal water potential, so no net water movement occurs, meaning no net change in mass of the potato cells.
2. Evidence: The linear fit line of % change in mass crosses 0% at the 0.2 M NaCl solution on the graph. A 0% change in mass means the potato cells neither gained nor lost mass in this solution.
3. Reasoning: When a solution is isotonic to a cell, the water potential of the solution and the cell is equal. This eliminates the concentration gradient that drives osmosis, so there is no net movement of water into or out of the potato cells, resulting in no change in mass.

Answer:

Claim:

The water potential of the Potato is equal to the 0.2 M NaCl solution.

Evidence:

The linear fit of the % Change in Mass crosses 0% at the 0.2 M NaCl concentration on the graph, indicating no net mass change for the potato in this solution.

Reasoning:

A 0.2 M NaCl solution is isotonic with the Potato cells. Isotonic solutions have equal water potential, so no net osmosis occurs, leading to no change in potato mass.