1. Water and Solutions
6.3

2. Water’s polarity Water molecules (H20) are polar.
When a molecule is polar, it means that it has oppositely charged regions.

3. Water’s polarity
Water’s polarity is what helps it form weak hydrogen bonds.

4. Mixtures with water
Mixture- combination of two or more substances in which each substance retains its individual characteristics and properties.
A mixture can be homogenous or heterogenous.
Homogenous- the prefix homo- means the same. When a mixture is homogenous, it is completely mixed up
Heterogeneous- the prefix heter- means different. When a mixture is heterogeneous, it is not completely mixed up, the individual parts are still separate.

5. Homogeneous mixtures
Solution- this is another name for a homogenous mixture. Think of contact solution, it’s all completely mixed up.
Solvent- this is the liquid in which other things dissolve. Water is a good solvent. This would be the water in contact solution.
Solute- this is the compound that is dissolved in the liquid. Think of this as the salt that is dissolved in the contact solution.

6. Mixtures with water
pH scale- the scale we use to determine how basic or acidic something is.
1-6.9-> acidic ex. Lemon juice
7-7.9-> neutral ex. Pure water
> basic ex. Milk
A buffer is something that can react with an acid or a base to keep it in a certain range.

7. Mixtures with water

8. Mixtures with water
Base- a substance that releases hydroxide (OH-) ions when it is dissolved in water.
Therefore, a solution that has a lot of hydroxide ions in it is basic.
Acid- a substance that releases Hydrogen (H+) ions when dissolved in water.
Therefore, a solution that has a lot of hydrogen ions in it is acidic.

9. Key points 6.3
Water is polar, meaning water molecules have different charges on different sides of the molecule.
Acids have a ph of 1-6.9
Bases have a pH of