2.  Salts do not contain H+ or OH- and dissociate when dissolved in H2O. ◦ Resulting ions will conduct electricity in the solution (electrolytes) ◦ Salts are common in the body  Calcium phosphate (hardness in teeth and bones)  Sodium & potassium (nerve impulses/muscle contraction)  Iron (hemoglobin)  Zinc& copper (enzyme activity)

3.  Acids and bases are electrolytes  Acids release hydrogen ion (H+) ◦ They are also called proton donors ◦ Concentration of H+ in the solution determines acidity. ◦ Hydrochloric acid (HCL), acetic acid (HC2H3O2), carbonic acid (H2CO3)

4.  Bases are proton acceptors ◦ They take up H+ and are also called hydroxides ◦ When dissolved in H2O, they release hydroxyl ions (OH-)  Eventually the OH- binds with a H+ already in the solution to make H2O  Reduces the acidity of the solution by removing H+ bicarbonate ion (HCO3-) in the blood, ammonia (NH3) as a waste product.

5.  pH is a measurement of the relative concentration of H+.  The more the H+ the more acidic the solution.  The more OH- the more basic the solution.  Scale is 0-14 with 7 being neutral, the high end basic and the low end of the scale acidic.  Each successive change of 1 pH unit represents a ten-fold change in the H+ ion concentration.

6.  Buffers counteract slight changes in the environmental pH. ◦ Critical to the survival of cells. ◦ Will release H+ ions if the pH rises ◦ Bind OH- ions if the pH drops ◦ Strong acids can dramatically change the pH of a solution. ◦ Weak acids do not affect pH as much.