**Preparing a 500 Gram Aqueous Solution of 15% Sucrose by Mass**

To prepare a 500-gram aqueous solution containing 15% sucrose by mass, you will need to follow these steps:

1. Determine the mass of sucrose needed:
- Mass of sucrose = Mass of solution × Percentage of sucrose
- Mass of sucrose = 500 g × 15% = 75 g

2. Measure 75 grams of sucrose:
- Use a weighing scale to accurately measure 75 grams of sucrose. Ensure that the scale is properly calibrated for accurate measurements.

3. Dissolve the sucrose in water:
- Take a clean beaker or container and add approximately 300-400 ml of distilled water.
- Slowly add the measured 75 grams of sucrose to the water while stirring continuously. Stir until all the sucrose is completely dissolved.

4. Add more water to reach the desired mass:
- After the sucrose is fully dissolved, add more distilled water to the beaker until the total mass of the solution reaches 500 grams. This additional water will account for the mass of the sucrose and any water lost during the dissolving process.

5. Stir the solution:
- Use a glass rod or a magnetic stirrer to ensure the solution is thoroughly mixed. This will help in achieving a uniform concentration of sucrose throughout the solution.

6. Verify the concentration:
- To ensure that the solution indeed contains 15% sucrose by mass, you can perform a simple calculation:
- Sucrose concentration = (Mass of sucrose ÷ Mass of solution) × 100
- Sucrose concentration = (75 g ÷ 500 g) × 100 = 15%

7. Label and store the solution:
- Once the solution is prepared and the concentration is verified, label the container with the solution's composition (15% sucrose by mass) and the date of preparation.
- Store the solution in a clean, sealed container at room temperature or as per the specific requirements of your application.

By following these steps, you will be able to prepare a 500-gram aqueous solution containing 15% sucrose by mass.

75grams of sucrose+425grams water