Objectives: Catalyst: Homework: Page 83, 17-22 I can classify a solution based on its pH. I can list some physical properties of acids and bases. I know the role of H+ and OH- in pH and know how the pH scale changes with H+ concentration. Catalyst: How would you know is something was acidic? Basic? Neutral? Which type of solution would you rather drink, an acid or a base? Why? Homework: Page 83, 17-22
pH What do you already know? Low pH means acidic High pH means basic/alkaline 7 is neutral
pH Mini-lab You and your table partners are going to test a number of household items using pH strips. Before you start, make a prediction about the pH of each item. Is it a…. Strong acid Weak acid Neutral Weak base Strong base You need to figure out a way to organize your data. The strips themselves can be part of your data table.
pH Mini-lab Sodium Hydroxide Hydrochloric acid Alka-seltzer Pepsi Sierra Mist Soap Rubbing alcohol Baking soda
Read C.9 Acids Bases Similarities
C.9 pH What is pH? - measure of the acidity of a solution - scale is from 0 to 14 - 0 is very acidic - 14 is very alkaline/basic - 7 is neutral - every step on the scale is 10 times more than the previous step - 5 is 10x more acidic than 6 - 4 is 100x more acidic than 6 - 3 is 1,000x more acidic than 6
C.9 pH What does pH mean? - pH is the “power of hydrogen” - OH– and H+ ions in solution change the pH - acids create more H+ in solution - HCl, HNO3, H2SO4 - bases create more OH– in solution - Ca(OH)2, KOH, NaOH - pH gives the concentration of H+ ions in solution - more H+ means more acidic, lower pH - more OH- means more basic, higher pH
C.9 Acids and Bases Acid + Base = a neutralization reaction Bases Corrosive Taste bitter Feel slippery React with oils and greases Acids Corrosive Taste sour Feel sticky React with metals Acid + Base = a neutralization reaction