Solutions and Concentrations

1. Preparation of 100 mL of a 0.0100 M Sucrose Solution

1. Determine the number of moles and mass of sucrose (C₁₂H₂₂O₁₁) to be dissolved in 100 mL of solution.
   
2. Weigh out the mass of sucrose on the balance. First place a weigh boat on the balance and set the “tare weight”. Then using a scoopula, carefully transfer solid solute from the reagent bottle to the weigh boat until the desired amount is obtained.
3. Place a powder funnel into a clean and dry 100-mL volumetric flask. Pour the solid from the weigh boat through the funnel into the flask.
4. Using a wash bottle containing distilled water (the solvent), rinse any remaining solid from the weigh boat through the funnel into the flask.
5. Add solvent using the distilled water faucet until the liquid level reaches the neck of the flask (but not the mark). Cap and swirl the flask gently to dissolve the solute.
6. Once all of the solute has dissolved, use a wash bottle to carefully add solvent until the liquid level reaches the mark.
7. Cap and invert the volumetric flask several times to ensure good mixing of the solution.

2. Making a Supersaturated Sucrose Solution

1. Add 100 mL of distilled water to a 600-mL beaker.
2. Add 220 g of sucrose to the beaker.
3. Place a magnetic stir bar in the beaker and allow the mixture to stir for 15 min.
4. Examine the mixture: not all of the sucrose has dissolved. Heat the mixture to 50 ºC and stir for an additional 10 min.
5. Examine the mixture: all of the sucrose has dissolved at 50 ºC.
6. Allow the solution to cool to room temperature. Examine the solution: the additional sucrose that dissolved at 50 ºC remains dissolved at room temperature. The solution at room temperature is supersaturated.