4 original questions from New Regents. The worksheet, answer key, and browser practice are free.
When a Seed Crystal Grows or Shrinks 4 questions
When a Seed Crystal Grows or Shrinks
Base your answers on the information provided and your knowledge of chemistry. Use the 2025 Chemistry Reference Tables as needed.
A display holds two sodium acetate solutions at 20 °C. Each has 100 g of water. The model tracks dry sodium acetate, and no water enters the crystal. At 20 °C the equilibrium capacity is 46 g sodium acetate per 100 g water. A technician adds an 8 g sodium acetate crystal to each clear solution. No sodium acetate or water leaves either tube.
| Tube | Solid added (g) | Solid remaining at equilibrium (g) | Dissolved at equilibrium (g) |
|---|---|---|---|
| P | 8 | 4 | 46 |
| Q | 8 | 14 | 46 |
Question 1
In which tube does sodium acetate move from the solid into solution on balance?
- P only
- Q only
- Both tubes
- Neither tube
Question 2
Calculate the mass of dissolved sodium acetate in each tube before the crystals were added. Show how the solid measurements enter the calculation.
Write your answer and work on the printable worksheet, or answer online.
Question 3
A student uses the matching final dissolved masses to argue that the starting solutions had the same concentration. Evaluate the claim with the solid readings and the water mass.
Write your answer and work on the printable worksheet, or answer online.
A repeat uses a fresh tube prepared with the same starting solution as P. The technician adds only 2 g of solid sodium acetate and allows the tube to reach equilibrium at 20 °C. The water mass remains 100 g.
Question 4
Predict the dissolved mass and the solid mass in the repeat. Explain whether the final dissolved mass reaches 46 g.
Write your answer and work on the printable worksheet, or answer online.
2025 Chemistry Reference Tables · Browse Chemistry worksheets