Acids and Bases Chemistry 1106

Definitions Arrhenius Acid Arrhenius BASE Releases Hydrogen ion (Proton) Produces H3O+ HNO3 + H2O → H3O+ + NO3- Arrhenius BASE Releases OH- ion (Hydroxyl) NaOH + H2O  Na+ + OH- + H2O

Strong vs. Weak Strong Acid/Base Completely Dissociates Only Few Strong Acids And Bases No Equilibrium HNO3 + H2O → H3O+ + NO3- NaOH + H2O → Na+ + OH- + H2O

Strong vs. Weak Weak Acid/Base Partially Dissociates Reaction Is In Equilibrium HF + H2O ↔ H3O+ + F-

pH Reference is Water In Pure Water (Equilibrium) pH = -log [H3O+] Water is Amphoteric- Characteristics of both acid and base H2O + H2O ↔ H3O+ + OH- In Pure Water (Equilibrium) [H3O+] = 1.0 x 10-7 [OH-] = 1.0 x 10-7 pH = -log [H3O+] Most water is not 7 Our is between 4-5

Correlations of pH pH Goes Down As [H3O+] Increases The higher the Ka the higher the Disassociation Is in -Log scale so… is a 10 fold difference Since H3O+ and OH- Ions Effect pH, It Can Be Said That: ↓ pH = ↑ Acidic Strength ↑ pH = ↑ Basic Strength

pH Electrode Working principle on current

Carefull pH electrode are very sensitive and very easy to break Never leave a pH electrode out of a solution Rinse electrode with DI water when introduce to a new solution Calibrate Electrode Check calibration curve with solutions pH 4 7 and 10 If valid go to experiment

Fill in the blanks Solutions are 1) H2O 2) oxlic acid 3) HCl 4) H2SO4 5) NaOH 6) NH4OH 7) Na2PO 3 8) Unknown A and B

Calculations pH = -Log[H3O+] // pOH = -Log[-OH] 10-pH= [H3O+] // 10-pOH= [-OH] pH + pOH = 14 Only in a strong acid this = the concentration