pH, Acids and Bases

pH? What is that?? pH: a mathematical measure of hydrogen ions and hydroxide groups in a solution

Measuring pH A solution is “acidic” if the pH is less than 7 A solution is “basic” if the pH is more than 7

Measuring pH pH scale- measures how acidic, basic, or neutral a substance is Ranges from 0-14 pH of 7= neutral pH of less than 7= acidic pH of more than 7= basic

Basic

What does this have to do with water? Pure distilled water is neutral (pH=7) When chemicals are mixed with water, the mixture can be acidic or basic The pH of a sample of water determines its quality

Acids Sour taste Conduct Electricity Red on pH paper Burn skin Contain Hydrogen Ions H+ Always willing to give a Hydrogen ion Characteristics of Acids: Sour taste Conduct Electricity Red on pH paper Burn skin

Bases Contain OH- groups / Hydroxides Always willing to accept a hydrogen ion Characteristics Slippery Feeling Conduct Electricity Blue on pH paper Burn skin

Neutralization H+ + OH- H20 When an acid and a base react, this is called a neutralization. The acid and the base balance each other out and move towards neutral (think average). The byproduct of neutralization is always water and any type of salt. H+ + OH- H20

Neutralization Examples: Strong Acid + Weak Base = Water and Acidic Salt Weak Acid + Strong Base = Water and Basic Salt Strong Acid + Strong Base = Water and Neutral Salt

Lab activity Ammonia Milk Vinegar Lemon juice Milk of Magnesia Hydrochloric Acid Rubbing Alcohol Bleach Tap Water

Common Items and their pH