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Tracking Salt Across a Model Tank 4 questions
Tracking Salt Across a Model Tank
Base your answers on the information provided and your knowledge of chemistry. Use the 2025 Chemistry Reference Tables as needed.
A tank model has two halves, A and B, with 0.200 L of water in each. Salt can move between the halves after a divider opens, and the model keeps each half well mixed. The volume of each half stays fixed, and no salt enters or leaves the tank during the first test.
| Time after opening (min) | A concentration (g/L) | B concentration (g/L) |
|---|---|---|
| 0 | 8.0 | 2.0 |
| 2 | 6.0 | 4.0 |
| 6 | 5.0 | 5.0 |
Question 1
Which reading first shows no concentration difference between the halves?
- The A reading at 0 min
- The B reading at 2 min
- The pair of readings at 6 min
- The pair of readings at 2 min
Question 2
Calculate the net mass of salt that moved into B during the first two minutes. Show how the volume enters the calculation.
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Question 3
Use both halves at the start and at six minutes to evaluate the claim that the decrease in A means salt left the tank.
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A repeat starts with the original amounts. At six minutes the new readings are 5.0 g/L in A and 4.0 g/L in B. The volumes are still 0.200 L, and the model confirms both readings.
Question 4
Use the new readings to decide whether movement between the halves alone can account for the result.
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