Objective:
To demonstrate how the solubility of a salt varies with temperature and plot the solubility curve of a salt on the basis of observed data.
Introduction:
Solubility is the maximum amount of substance that will dissolve at a specific temperature. The units for solubility are grams of solute/ 100 grams of solvent. A solute is the substance being dissolved. A solvent is present in greater amount. The solubility of a solute is defined as the amount of solute that will dissolve in a given amount of solvent to make a saturated solution. The solubility of a substance is not constant (it varies with different conditions, like temperature). The independent variable is the mass of ammonium chloride. The …show more content…
thermometer
8. hot plate
Procedures:
1. Label 4 test tubes as follows: 2.00, 2.50, 3.00, and 3.50.
2. Weigh 2.00 g, 2.50 g, 3.00 g, and 3.50 g of ammonium chloride. Place each sample in its correct labeled test tube.
3. Add 5.0 mL of water into each test tube using a pipette.
4. Using a hot plate, fill the beaker with water half way, place both the 2.00 and 2,50 gram samples in the water, and bring the water to a boil.
5. While this is happening, start to heat the test tube containing the 3.50 grams sample with an alcohol burner. Continuously stir until the solute has completely dissolved. Make sure that the contents in the test tube do not start to boil.
6. Place the thermometer into the solution, allow the contents to cool down while stirring.
7. When the first crystals start to appear make sure to record the temperature at which the solid began to crystallize.
8. Heat the solution in the test tube again in order to dissolve the crystals, allow it to cool again, and record the new temperature at which crystallization occurs.
9. Repeat the same steps with the test tube containing the 3.00 gram sample.
10. Repeat the same steps with the test tubes containing the 2.00 and the 2.50 gram samples using the hot water bath as the