Start learning today, and be successful in your academic & professional career. Start Today!

• ## Related Books & Services

 0 answersPost by harsh patel on April 26, 2012i thought that the conjugate of a weak acid was a strong base?? 0 answersPost by YiÄŸit ALTINSEL on April 19, 2012Determine the pH of a solution that is 0.125 M in CO32-. (For H2CO3, Ka1=4.3x10-7, Ka2=5.6x10-11)How is the solution of this problem? 3 answersLast reply by: Marian IskandarThu May 2, 2013 1:44 AMPost by Erin M on April 14, 2010Where are these supplemental problems? The one's on video, or is there a link on this site that will provide me extra questions?

### pH Calculations, Polyprotic Acids

• Use approximations (the 5% rule) in calculating pH in solutions of weak acids or bases

• Conjugate bases of weak acids are weak bases and vice-versa

• For conjugates KaKb = Kw

• Do calculations of pH in solutions of conjugates like acetate and ammonium ions

• For polyprotic acids successive Ka values get (much) smaller

• Do calculations of pH in solutions of phosphoric acid, phosphate salts

### pH Calculations, Polyprotic Acids

Lecture Slides are screen-captured images of important points in the lecture. Students can download and print out these lecture slide images to do practice problems as well as take notes while watching the lecture.

• Intro 0:00
• pH in a Solution of a Weak Acid 0:45
• Vinegar (Acetic Acid)
• Example: pH of Acetic Acid Solution
• pH in a Solution of a Weak Base 9:42
• Ammonia
• Example: pH of Pyridine Solution
• Salts of Weak Acids with Strong Bases 17:15
• Example: Acetic Acid and Sodium Hydroxide
• Salts of Weak Bases with Strong Acids 20:55
• Example: Ammonia and Hydrochloric Acid
• Conjugate Acid Base Pairs: Ka and Kb 22:58
• Example: Acetic Acid Ionization
• Polyprotic Acids: Successive Ka Values 28:50
• Example: Diprotic Acid (Sulfuric Acid)
• Example: Tripotic Acid (Phosphoric Acid)
• pH in a Polyprotic Acid Solution 41:02
• Example: Phosphoric Acid Solution pH
• Salts of Polyprotic Acids 47:32
• Examples: TSP, Tartaric Acid