6.5 a, b, c. Did you know that water that comes from the tap isn't pure water? Tap water is a...

6.5 a, b, c

Did you know that water that comes from the tap isn't pure water?

Tap water is a mixture of pure water (H2O) and a variety of other substances such as chloride, fluoride and metallic ions. Gases such as oxygen and carbon dioxide are also dissolved in water.

Tap water can differ from home to home because it is a mixture.

Suspension= is a mixture in which particles can be seen and easily separated by settling or filtration. It is not evenly mixed.

Example: water mixed with pepper

Solution= a mixture that has the same properties throughout. It is well-mixed.

Examples: tap water and salt water

Dissolved particles in solutions are much smaller than suspended particles.

Dissolved particles do not settle out of a solution and they pass through a filter.

Exception: salt can be separated from water by boiling or letting the water evaporate.

All solutions have at least 2 parts: the solvent and one or more solutes.

Solvent= does the dissolving (largest amount)

Solute= is dissolved by solvent (smallest amount)

In a solution of table salt and water: solvent= water solute= table salt

Water is the solvent in many solutions:

Soda Blood Saliva Tears Sap (solution that carries water to

tree cells) Water in the soil mixed with plant

nutrients Can you think of others?

When a solution contains the maximum amount of solute, it is a saturated solution.

Any extra solute settles to the bottom.

Colloid= a mixture with small undissolved particles that do not settle out.

It is different from both a solution and a suspension:

Particles are larger than particles in a solution but not as large as particles in a suspension.

The particles are large enough to affect the way light passes through them.

Examples: jello, fog, mayonnaise, shaving cream, whipped cream

Some solutes can have an effect on solutions:

They can lower the freezing point of a solvent, or the temperature at which a substance freezes. (liquid → solid) example: making ice cream using rock salt

They can raise the boiling point of a solvent, or the temperature at which a substance boils. (liquid → gas) example: adding salt to water when

cooking spaghetti