Term |
Definition |
solvent |
The solvent is the component whose phase is retained when the solution forms; if all components are the same phase, the one in the greatest amount is the solvent. If one of the components is water, water is always the solvent. |
solute |
The solute is the component(s) in the smallest amount. |
dissolution |
The process of a solute dissolving in a solvent is called dissolution (dissolving). |
concentration |
The concentration of the solution is the amount of solute in a given amount of solvent. |
unsaturated |
Is a solution which can dissolve more solute. |
saturated |
Is a solution with the dissolved solute in equilibrium with the undissolved solute. |
supersaturated |
Is a solution holding more dissolved solute than would be in equilibrium with the undissolved solute |
When sodium chloride is added to water no dramatic chemical change is observed.
|
When sodium metal is added to water a dramatic chemical change is observed.
|
1. It is a homogeneous mixture of two or more substances.
2. It can be colorless, or exhibit color, but is transparent.
3. The solute is uniformily distributed throughout the solvent and will not settle out in time.
4. The solute can be separated from the solvent by physical means.
Solute |
Solvent |
gas |
gas |
gas |
liquid |
liquid |
liquid |
solid |
liquid |
gas |
solid |
liquid |
solid |
solid |
solid |
For a particulate level view of the solution process we will look at a model developed by concord.org. |
---|
In liquid molecular solutions, when both the solute and solvent are covalent compounds, the intermolecular attractive forces are London dispersion, dipole-dipole and hydrogen bonding.For a particulate level view of the solution process we will look at a model developed by concord.org. |
---|
1) solvent-solvent intermolecular attractions
2) solute-solute intermolecular attractions
3) solute-solvent intermolecular attractions
When we try to dissolve a solid in a liquid the attractive forces
are at a maximum in the solid. In order for the solid to dissolve in the liquid
the solvent-solvent forces of attraction must be sufficient to overcome the
attractive forces that hold the solid together. In molecular crystals the attractive
forces are weak being of the London dispersion, dipole-dipole or hydrogen-bonding
type. The solubility of molecular solids in molecular solvents is again governed
by the like dissolves like principle.
|
---|
View the movie of the dissolution of NaCl in water.1. What color are the sodium ions, Na+, and the chloride ions, Cl-, in the video? Answer2. What are the attractions that try to keep the sodium ions and chloride ions in the solid phase? Answer3. What are the attractive forces between the ions and the water molecules? AnswerThe movie you are looking at was captured from a simulation available at concord.org. The link Concord.org animation of dissolution of NaCl in water is http://mw.concord.org/modeler/showcase/simulation.html?s=http://mw2.concord.org/public/student/solution/dissolve.html . This link will run in Safari 11, but not in Safari 12. It will also run in Windows 10. |
1) Change in enthalpy (exothermic or endothermic) in the solution process
2) Change in entropy (measure of disorder)