Solutions & Suspensions

CP Biology

ATB: Is it Cohesion or Adhesion?

1. 2.

3. 4.

What does it mean to say water is polar?

How does water’s polarity help it with hydrogen bonding?

How does hydrogen bonding cause ice to be less dense than water?

Water Review

Water has multiple hydrogen bonds so it takes a lot of heat to cause those molecules to move faster (raising the temperature).

Water’s heat capacity is high. Large bodies of water can absorb a lot of

heat with only small changes in temperature.

Is the weather more constant in Hawaii or New Mexico?

Heat Capacity

A mixture is a material composed of two or more elements or compounds that are physically mixed but not chemically combined.

What is a mixture?

Images from bright hub education

Are these mixtures?

GBJ.com

Air Blood

Ocean water

Mixtures are categorized into 1) solutions and 2) suspensions.

All components of a solution are evenly distributed throughout a solution.

Solute: the substance that is dissolved Solvent: the substance in which the solute

dissolves

example: water and salt

Solutions

Water’s polarity allows it to dissolve both ionic compounds and polar molecules.

When water has dissolved as much as it can hold, it is called saturated.

Water’s Polarity Makes it a Solvent!

Image from Pearson

Image from SUNY

Some materials do not dissolve and settle into small particles

The movement of water keeps them suspended

Suspensions are mixtures of water and undissolved material

Suspensions

Water molecules often split apart to form ions.

The pH scale is a measurement systems that indicates the concentration of H+ ions in solution.

pH of 7 is neutral because the concentration of H+ and OH- is equal

The lower the pH, the more acidic

The higher the pH, the more basic.

Acids, Bases & pH

Solutions with a pH below 7 are called acidic because they have more H+ ions than OH- ions.

Solutions with a pH above 7 are called basic because they have more OH- ions than H+ ions.

Each step on the pH scale represents a factor of 10. A liter of solution with a pH of 4 has 10 times as many H+ ions as a liter of solution with a pH of 5.

pH Scale

Image from Pearson