mixtures water ph honors biology mixture: a combination of two or more substances that are...
TRANSCRIPT
Mixture:A combination of two or more
substances that are physically mixed
They are not chemically combined!!Examples: soil, salsa, trail mix, milk &
cereal, sugar water.
Types of Mixtures:
A. Solution: A mixture formed when one substance dissolves in another- molecules are evenly distributed.
1. Solute: the substance that is dissolved in a solution
2. Solvent: the substance that does the dissolving.
Example: salt water
solute=salt, solvent=water
Parts of a Solution :
1. Solute: the substance that is dissolved in a solution
2. Solvent: the substance that does the dissolving.
Parts of a Solution :
B. Suspension: Mixture of water and non-dissolved materials
(In between a Mixture and Solution)A Colloid: A suspension where you can’t see
materials with naked eye
Examples: Blood, Milk
Now test what you learned:
Indicate whether each is a mixture, solution or suspension.
Unknown #1: Mixture
Salt & Pepper
Special Type of SolutionEmulsion – a type of Colloid
An emulsion is a suspension of two liquids that usually do not mix together.
For example if we mix oil and water a suspension will form that over time separates. But now, if we add a few drops of a third substance, the emulsifier, and shake the mixture the oil and water will stay mixed much longer.
Examples of emulsions include butter and margarine, and mayonnaise.
Water: Needed for Life
Water has several properties that make it necessary for life.
It is POLAR - It has area with a slight positive charge, and an area with a slight negative charge.
Water: Needed for Life
Hydrogen Bonding allows one water molecule to “stick” to another water molecule.
Water: CohesionCohesion is the ability for water molecules
to stick to themselves
Beads of WaterSurface Tension
Water: Adhesion
Adhesion is the ability for water molecules to stick to other materials
Meniscus in a graduated cylinder
Water: A Great Solvent
Remember… A solvent has the ability to
dissolve other materials
Water is a solvent for many things
For example: The liquid part of your blood (the plasma) is 90% water
Some items, such as fats and oils DO NOT dissolve in water.
pH: What is it?
Some compounds break up into ions when they dissolve in water.
Solutions with more H+ ions are more ACIDIC They have a LOW pH (<7)
Solutions with less H+ ions are more BASIC They have a HIGH pH (>7)
H2O H+ + OH-
pH: What is it?
Some properties of acids and bases
pH Example Characteristics
Acids
Neutral
Bases
< 7
= 7
> 7
Lemon vinegar soda, aspirin
Sour, burns, dissolves things
Pure Water ------
Soap,baking soda, ammonia
Bitter, Slippery
pH: Looking at common items
Battery Acid
pH = 0
Orange Juice
pH = 3
Ocean Water
pH = 8
Oven Cleaner
pH = 13
pH: Importance to Humans
Blood has a pH of 7.4 (about neutral)
If pH goes below 6.8 or above 7.8 it is deadly!
To keep blood at the proper pH - our body uses buffers