pH Scale

Acids and bases Acids and bases are of enormous importance in general chemistry, since they provide an effective way of understanding the properties of solutions and the chemical activity that lies within. Acid/base chemistry is central to: oxidation/reduction reactions numerous bodily functions to maintain homeostasis play a crucial role in the environment

pH scale pH (potential of Hydrogen) is a measure of acidity or alkalinity (base). Substances are assigned a number according to the number of hydrogen H+ ions it contains. Scale of 0 to 14.

pH Scale Acid: Less than 7. Adding hydrogen H+ ions Base (alkaline): Greater that 7. Creates – OH ions Why is water neutral? Water (H 2 O) is the universal solvent and is neutral with a pH of 7. Water has as an equal balance of H+ ions and - OH ions.

pH Scale A change on the scale of one (1) means a tenfold change in H+ concentration. The value of pH is measured in negative by the H+ concentration in moles per liter.

Properties of Acids Acids can be characterized by; – Sour taste – Sharp smell – Reacts with metals & carbonates – Examples: hydrochloric acid, nitric acid, sulfuric acid, and citric acid

Properties of Bases Bases (Alkaline) can be characterized by; – Bitter taste – Slippery feel – Produces CO 2 – Examples: sodium hydroxide, bleach, calcium hydroxide, & ammonia

Remember….. As the H+ increases the pH level decreases

Neutralization A mixture of specific concentrations and amounts of acid and base to neutralize a reaction.

“Salt” Salt NaCl (Sodium Chloride) is not the only salt. Salt is any compound created from neutralizing an acid and a base. Water is also a byproduct of neutralization.