Question

if the line cross concentration (m) twice one at 0.3M and reach -10.04% and goes or rise Up crossing at 0.5M and then comes down at 0.7M to 14.53% another one at 0.7M. how can i calculate and determine the molarity for potato cell?

Answer 1

To determine the molarity of the potato cell (also referred to as osmotic potential or solute potential), you can use the data from the concentrations and the corresponding percentages to find the point at which there is no net movement of water, which indicates the isotonic point.

Based on your description, it seems you have a set of concentration values (0.3 M, 0.5 M, and 0.7 M) along with their respective percentage changes in weight (or some other metric). You mentioned that at 0.3 M the change is -10.04%, and at 0.7 M it's 14.53%.

The typical approach to solve for the molarity of the potato cell would involve the following steps:

1. **Identify the Isotonic Point:** Since the potato cells lose water in the 0.3 M solution (indicating that the surrounding solution is hypertonic), and gain water in the 0.7 M solution (indicating that the surrounding solution is hypotonic), the point where there is no net change in weight (0% change) would indicate the isotonic point.

2. **Analyze Given Data:**
- At **0.3 M**, the change is **-10.04%** (water moving out of the cells).
- At **0.5 M**, the change is unknown, but you might expect it to be closer to 0% than at 0.3 M.
- At **0.7 M**, the change is **14.53%** (water moving into the cells).

3. **Estimate the Isotonic Concentration:** The isotonic point typically lies between the concentrations at which water movement occurs:
- Since 0.3 M shows a negative change and 0.7 M shows a positive change, you can estimate that the isotonic point is between these two.

4. **Interpolation to Find Isotonic Concentration:** If you further measured the change at the 0.5 M solution and found it to approach 0% (assuming it is indeed between the two concentrations), then you could say that the molarity of the potato cell is approximately **0.5 M** or slightly below.
- If you can graph the percentage change against concentration, the point where the graph crosses the x-axis (0% change) will give you a more precise estimate for the isotonic concentration.

In conclusion, assuming the data behaves linearly, the molarity for the potato cell is likely around **0.5 M**, given the changes observed at 0.3 M and 0.7 M. However, precise measurement at the 0.5 M concentration is recommended to confirm the exact point where there is no net gain or loss of water.