A subscription to JoVE is required to view this content.
You will only be able to see the first 20 seconds.
At the end of this lab, students should know...
Solubility describes how much solute can dissolve in a solvent. This depends on the dissolution process between the solute and the solvent, so a solute will have different solubilities in different solvents.
Solubility is affected by the temperature of the system. You should always check what temperature is associated with a solubility value. Solubility usually increases with temperature, but there are exceptions.
The phrase “like dissolves like” reminds us that polar solutes typically have good solubility in polar solvents and poor solubility in nonpolar solvents, while nonpolar solutes typically have good solubility in nonpolar solvents and poor solubility in polar solvents.
A saturated solution contains the maximum amount of dissolved solute given the volume and temperature of the solvent. The dissolution and precipitation of the solute are in equilibrium, so the overall rates of dissolution and precipitation are the same.
The change in entropy of a solution tells us whether the dissolution reaction is completely reversible. The change in enthalpy of a solution tells us whether heat was absorbed or released during dissolution. The change in Gibbs energy tells us whether the dissolution was spontaneous or whether the system required additional energy to dissolve the solute.
Source: Smaa Koraym at Johns Hopkins University, MD, USA
Here, we show the laboratory preparation for 10 students working in pairs, with some excess. Please adjust quantities as needed.
|1 Ring stand|
|1 Burette clamp|
|1 50-mL glass burette|
|1 Thermometer clamp|
|1 Digital thermometer|
|1 Glass thermometer|
|1 Long-stem funnel|
|1 5-mL volumetric pipette|
|1 10-mL capacity pipetter|
|1 50-mL graduated cylinder|
|5 250-mL Erlenmeyer flasks|
|2 400-mL beakers|
|1 150-mL beaker|
|1 Stirring hotplate|
|1 Stir bar|