1. Solutions and Solubility

2. Mixtures
Solutions are a type of mixture, so to understand solutions, first we have to know what a mixture is…
A mixture is a combination of two or more substances. Each substance keeps it’s own properties, even though it is mixed with another substance. They do not combine to form a new chemical substance

3. Mixtures
Mixtures are all around us: raisin bran, cakes, soda, soup, salad, rocks, sweet tea, trail mix, etc.

4. Mixtures There are 2 types of mixtures:
Homogeneous mixtures: everything in the mixture is even spread out and thoroughly mixed
If you took 2 spoonfuls of this type of mixture, they would be exactly alike
Heterogeneous mixtures: there is more of 1 substance than another and they are not evenly spread out and thoroughly mixed
If you took 2 spoonfuls of this type of mixture, they would not be exactly the same

5. Solutions Solutions are a type of homogeneous mixture
We call it a solution when 1 substance dissolves into another substance
An example is sweet tea…the sugar dissolves in the tea
Another example is soda…the carbon dioxide dissolves in the liquid soda
Another example is air…the oxygen dissolves in the
nitrogen
Another example is a metal alloy like steel, made of iron and carbon

6. Solutions We give special names to the substances in a solution
The material that is doing the dissolving is called the solvent.
So many things dissolve in water that they call it the “Universal Solvent.” It is the most common solvent
The material that is being dissolved is called the solute.
There is usually more solvent in a solution than solute

7. Solutions
With our sweet tea example, the tea would be the solvent and the sugar would be the solute.

8. Solutions
By now you should see, solutions aren’t always solids and liquids
Gas-Gas
Air
Gas-Liquid
Carbon Dioxide in Soda
Liquid-Liquid
Gasoline
Liquid-Solid
Dental Fillings
Solid-Solid
Sterling Silver

9. Solubility
Solubility is the amount of solute that can be dissolved in a specific volume of solvent under certain conditions
Solubility basically tells us how well the solute will dissolve in the solvent

10. Solubility Several factors can affect solubility
Temperature of the solvent
You can dissolve more sugar in hot tea than you can in cold tea
You can dissolve less gas in a hot liquid than in a cold liquid
Pressure of the system
A closed soda can has more carbon dioxide in it than an open one because the closed can is under pressure

11. Solubility The Chemical Nature of the Solvent
Some solvents, like water, naturally dissolve more substances than other solvents do.
Stirring and Particle Size can affect how fast a solute dissolves in a solvent

12. Saturation
A solvent is said to be “saturated” when it is holding as much solute as it possibly can and if you add any more solute, it will start to come out of solution
An example is when you have extra sugar at the bottom of your sweet tea. The tea can’t hold any more sugar…it is saturated.

13. Solubility is not affected by the amount of matter present
Solubility is not affected by the amount of matter present. It is just like density, melting point and boiling point in that way

14. References