By Aviraj Singh
The solubility of most solid substances is generally said to increase as the temperature of the solvent increases. However, some substances, such as ytterbium sulfate, do the opposite. This can be explained through the Second Law of Thermodynamics which states that “in all energy exchanges, if no energy enters or leaves the system, the potential energy of the state will always be less than that of the initial state” (Farabee, 2010). When a solution is heated, the kinetic energy increases, it becomes easier for the particles to move between the two phases of solid and solution. The aforementioned law predicts that these particles will “shift to the more disordered, more highly dispersed, and therefore, more probably solution state” (Bishop, 2010). In contrast, gas solutions perform the opposite; in other words, they behave similar to substances like ytterbium sulfate. Unlike solids and liquids, increasing temperature decreases the solubility of gases, meaning that decreasing the temperature of the system will increase the solubility of gases. In this experiment, the effect of temperature on the solubility of potassium nitrate, KNO3, in the universal solvent, water, will be analyzed.
To determine the effect of temperature on the solubility of potassium nitrate, KNO3, in water. General Safety:
* Use test tube holders when removing test tubes from hot water bath * Use gloves to remove hot water bath from hot plate
* 4 Test tubes
* 10-mL graduated cylinder
* 2 Weigh boats
* Glass stirring rod
* Wash bottle
* Hot water bath
* Electronic balance
1. Label test tubes 1 through 4, respectively.
2. Add the following masses of KNO3 to the test tubes: 1.00 g, 2.00 g, 3.50 g, and 5.00g, respectively. 3. Without allowing the water to boil, heat about ½...