Acids & Bases
description
Transcript of Acids & Bases
![Page 1: Acids & Bases](https://reader035.fdocuments.net/reader035/viewer/2022062309/5681500a550346895dbde3c4/html5/thumbnails/1.jpg)
Acids & Bases
Calculating Ka from % Dissociation
Polyprotic AcidsProperties of Salts
![Page 2: Acids & Bases](https://reader035.fdocuments.net/reader035/viewer/2022062309/5681500a550346895dbde3c4/html5/thumbnails/2.jpg)
Example
• Lactic acid (HC3H5O3) is a waste product that accumulates in the muscle during exertion, leading to pain & a feeling of fatigue. A 0.100 M solution is 3.7% dissociated. Calculate Ka.
![Page 3: Acids & Bases](https://reader035.fdocuments.net/reader035/viewer/2022062309/5681500a550346895dbde3c4/html5/thumbnails/3.jpg)
Example
I
C
E
HC3H5O3 H+ + C3H5O3 -
![Page 4: Acids & Bases](https://reader035.fdocuments.net/reader035/viewer/2022062309/5681500a550346895dbde3c4/html5/thumbnails/4.jpg)
Polyprotic Acids
• More that one ionizable H+
• H+ come off one at a time
• Each one has a specific Ka value
• Ka1>>>>Ka2>>Ka3
• When calculating the pH of a polyprotic acid, you only use the 1st Ka because all of the others are so small
![Page 5: Acids & Bases](https://reader035.fdocuments.net/reader035/viewer/2022062309/5681500a550346895dbde3c4/html5/thumbnails/5.jpg)
Complete Ionization
• Write the steps for the complete ionization of H2Se
![Page 6: Acids & Bases](https://reader035.fdocuments.net/reader035/viewer/2022062309/5681500a550346895dbde3c4/html5/thumbnails/6.jpg)
Complete Ionization
• Write the steps for the complete ionization of H3AsO
![Page 7: Acids & Bases](https://reader035.fdocuments.net/reader035/viewer/2022062309/5681500a550346895dbde3c4/html5/thumbnails/7.jpg)
Example
• Calculate the pH & the [ ] of all species of a 3.0 M solution of H3PO4.
• Ka1 = 7.5 x 10-3, Ka2 = 6.2 x 10-8, Ka3 = 4.8 x 10 -13
![Page 8: Acids & Bases](https://reader035.fdocuments.net/reader035/viewer/2022062309/5681500a550346895dbde3c4/html5/thumbnails/8.jpg)
ExampleH3PO4 H+ + H2PO4
- Ka1 = 7.5 x 10-3
I
C
E
![Page 9: Acids & Bases](https://reader035.fdocuments.net/reader035/viewer/2022062309/5681500a550346895dbde3c4/html5/thumbnails/9.jpg)
ExampleH2PO4
- H+ + HPO4
-2 Ka1 = 6.2 x 10-8
I
C
E
![Page 10: Acids & Bases](https://reader035.fdocuments.net/reader035/viewer/2022062309/5681500a550346895dbde3c4/html5/thumbnails/10.jpg)
ExampleHPO4
-2 H+ + PO4
-3 Ka3 = 4.8 x 10-13
I
C
E
![Page 11: Acids & Bases](https://reader035.fdocuments.net/reader035/viewer/2022062309/5681500a550346895dbde3c4/html5/thumbnails/11.jpg)
Example
• pH =
• [H3PO4] =
• [H2PO4-] =
• [HPO4-2] =
• [PO4-3] =
• [H+] =
![Page 12: Acids & Bases](https://reader035.fdocuments.net/reader035/viewer/2022062309/5681500a550346895dbde3c4/html5/thumbnails/12.jpg)
Acid Base Properties of Salts
• Salts of weak acids produce basic solutions
• NaC2H3O2
![Page 13: Acids & Bases](https://reader035.fdocuments.net/reader035/viewer/2022062309/5681500a550346895dbde3c4/html5/thumbnails/13.jpg)
Acid Base Properties of Salts
• Salts of weak bases produce acidic solutions
• NH4Cl
![Page 14: Acids & Bases](https://reader035.fdocuments.net/reader035/viewer/2022062309/5681500a550346895dbde3c4/html5/thumbnails/14.jpg)
Acid Base Properties of Salts
• Salts of strong acids & Bases produce neutral solutions
• NaCl
![Page 15: Acids & Bases](https://reader035.fdocuments.net/reader035/viewer/2022062309/5681500a550346895dbde3c4/html5/thumbnails/15.jpg)
Calculations with salts
• KaxKb = Kw
• Can find Ka or Kb with this equation
• On AP formula sheet
![Page 16: Acids & Bases](https://reader035.fdocuments.net/reader035/viewer/2022062309/5681500a550346895dbde3c4/html5/thumbnails/16.jpg)
Example
• What is the pH if a 0.140M solution of NaC2H3O2 (Ka HC2H3O2 = 1.8x10-5)
I
C
E
![Page 17: Acids & Bases](https://reader035.fdocuments.net/reader035/viewer/2022062309/5681500a550346895dbde3c4/html5/thumbnails/17.jpg)
Another example
• What is the pH of a 0.140M solution of diethylaminochloride (C2H5)2NH3Cl.
• Kb (C2H5)2NH3+ = 1.3x10-3
• (C2H5)2NH3Cl (C2H5)2NH3+ + Cl-
• (C2H5)2NH3+ + H2O (C2H5)2NH2 + H3O +
I
C
E
![Page 18: Acids & Bases](https://reader035.fdocuments.net/reader035/viewer/2022062309/5681500a550346895dbde3c4/html5/thumbnails/18.jpg)
Qualitative Predictions of pH
• Ka>Kb acidic
• Kb>Ka basic
• Ka = Kb neutral
![Page 19: Acids & Bases](https://reader035.fdocuments.net/reader035/viewer/2022062309/5681500a550346895dbde3c4/html5/thumbnails/19.jpg)
pH Predictions
• Predict if an aqueous solution of the following are acidic, basic, or neutral
• NH4C2H3O2
• Kb NH4+ = 1.8x10-5
• Ka HC2H3O2 = 1.8x10-5
![Page 20: Acids & Bases](https://reader035.fdocuments.net/reader035/viewer/2022062309/5681500a550346895dbde3c4/html5/thumbnails/20.jpg)
pH Predictions
• Predict if an aqueous solution of the following are acidic, basic, or neutral
• NH4CN
• Kb NH4+ = 1.8x10-5
• Ka HCN= 6.2x10-10
![Page 21: Acids & Bases](https://reader035.fdocuments.net/reader035/viewer/2022062309/5681500a550346895dbde3c4/html5/thumbnails/21.jpg)
Effect of Structure of Acid Base Properties
• Weak acid (HF) Stays together
• Strong acids Look at
electronegativity
![Page 22: Acids & Bases](https://reader035.fdocuments.net/reader035/viewer/2022062309/5681500a550346895dbde3c4/html5/thumbnails/22.jpg)
Effect of Structure of Acid Base Properties