What are they? • A way to classify a substance based on the pH scale • pH is a measurement of the amount of hydrogen ions (hydrogen ion is +, did this gain or lose an electron?) • Scale of 0 to 14 • Substances less than 7 are considered an acid • Substances more that 7 are considered to be a base • Pure water is given a pH of 7
Acids • Produce H+ (as H3O+) ions in water • Produce a negative ion (-) too • Taste sour • Corrode metals • React with bases to form salts and water
Bases • Produce OH- ions in water • Taste bitter, chalky • Are electrolytes • Feel soapy, slippery • React with acids to form salts and water
Learning Check Describe the solution in each of the following as: 1) acid 2) base or 3)neutral. A. ___soda B. ___soap C. ___coffee D. ___ blood E. ___ water F. ___ grapefruit
Answers Describe each solution as: 1) acid 2) base or 3) neutral. A. _1_ soda B. _2_ soap C. _1_ coffee D. _1_blood E. _3_ water F. _1_ grapefruit
Learning Check 2! Identify each as characteristic of an A) acid or B) base ____ 1. Sour taste ____ 2. Produces OH- in aqueous solutions ____ 3. Chalky taste ____ 4. Produces H+ in aqueous solutions
Solutions Identify each as a characteristic of an A) acid or B) base _A_ 1. Sour taste _B_ 2. Produces OH- in aqueous solutions _B_ 3. Chalky taste _A_4. Produces H+ in aqueous solutions
Exit Slip • What do you think this has to do with what we’re learning?