Salts, Acids, Bases and pH

Salts 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)

Acids and Bases 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)

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.

pH 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.

Buffers 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.