Study Aids:
Click the Study Aids tab at the bottom of the book to access your Study Aids (usually practice quizzes and flash cards).
Study Pass:
Study Pass is our latest digital product that lets you take notes, highlight important sections of the text using different colors, create "tags" or labels to filter your notes and highlights, and print so you can study offline. Study Pass also includes interactive study aids, such as flash cards and quizzes.
Highlighting and Taking Notes:
If you've purchased the All Access Pass or Study Pass, in the online reader, click and drag your mouse to highlight text. When you do a small button appears – simply click on it! From there, you can select a highlight color, add notes, add tags, or any combination.
Printing:
If you've purchased the All Access Pass, you can print each chapter by clicking on the Downloads tab. If you have Study Pass, click on the print icon within Study View to print out your notes and highlighted sections.
Search:
To search, use the text box at the bottom of the book. Click a search result to be taken to that chapter or section of the book (note you may need to scroll down to get to the result).
View Full Student FAQs
Chapter 27 Appendix C: Dissociation Constants and pKa Values for Acids at 25°C
| Name | Formula | K a1 | pKa1 | K a2 | pKa2 | K a3 | pKa3 | K a4 | pKa4 |
|---|---|---|---|---|---|---|---|---|---|
| Acetic acid | CH3CO2H | 1.75 × 10−5 | 4.756 | ||||||
| Arsenic acid | H3AsO4 | 5.5 × 10−3 | 2.26 | 1.7 × 10−7 | 6.76 | 5.1 × 10−12 | 11.29 | ||
| Benzoic acid | C6H5CO2H | 6.25 × 10−5 | 4.204 | ||||||
| Boric acid | H3BO3 | 5.4 × 10−10* | 9.27* | >1 × 10−14* | >14* | ||||
| Bromoacetic acid | CH2BrCO2H | 1.3 × 10−3 | 2.90 | ||||||
| Carbonic acid | H2CO3 | 4.5 × 10−7 | 6.35 | 4.7 × 10−11 | 10.33 | ||||
| Chloroacetic acid | CH2ClCO2H | 1.3 × 10−3 | 2.87 | ||||||
| Chlorous acid | HClO2 | 1.1 × 10−2 | 1.94 | ||||||
| Chromic acid | H2CrO4 | 1.8 × 10−1 | 0.74 | 3.2 × 10−7 | 6.49 | ||||
| Citric acid | C6H8O7 | 7.4 × 10−4 | 3.13 | 1.7 × 10−5 | 4.76 | 4.0 × 10−7 | 6.40 | ||
| Cyanic acid | HCNO | 3.5 × 10−4 | 3.46 | ||||||
| Dichloroacetic acid | CHCl2CO2H | 4.5 × 10−2 | 1.35 | ||||||
| Fluoroacetic acid | CH2FCO2H | 2.6 × 10−3 | 2.59 | ||||||
| Formic acid | CH2O2 | 1.8 × 10−4 | 3.75 | ||||||
| Hydrazoic acid | HN3 | 2.5 × 10−5 | 4.6 | ||||||
| Hydrocyanic acid | HCN | 6.2 × 10−10 | 9.21 | ||||||
| Hydrofluoric acid | HF | 6.3 × 10−4 | 3.20 | ||||||
| Hydrogen selenide | H2Se | 1.3 × 10−4 | 3.89 | 1.0× 10−11 | 11.0 | ||||
| Hydrogen sulfide | H2S | 8.9 × 10−8 | 7.05 | 1 × 10−19 | 19 | ||||
| Hydrogen telluride | H2Te | 2.5 × 10−3‡ | 2.6‡ | 1 × 10−11 | 11 | ||||
| Hypobromous acid | HBrO | 2.8 × 10−9 | 8.55 | ||||||
| Hypochlorous acid | HClO | 4.0 × 10−8 | 7.40 | ||||||
| Hypoiodous acid | HIO | 3.2 × 10−11 | 10.5 | ||||||
| Iodic acid | HIO3 | 1.7 × 10−1 | 0.78 | ||||||
| Iodoacetic acid | CH2ICO2H | 6.6 × 10−4 | 3.18 | ||||||
| Nitrous acid | HNO2 | 5.6 × 10−4 | 3.25 | ||||||
| Oxalic acid | C2H2O4 | 5.6 × 10−2 | 1.25 | 1.5 × 10−4 | 3.81 | ||||
| Periodic acid | HIO4 | 2.3 × 10−2 | 1.64 | ||||||
| Phenol | C6H5OH | 1.0 × 10−10 | 9.99 | ||||||
| Phosphoric acid | H3PO4 | 6.9 × 10−3 | 2.16 | 6.2 × 10−8 | 7.21 | 4.8 × 10−13 | 12.32 | ||
| Phosphorous acid | H3PO3 | 5.0 × 10−2* | 1.3* | 2.0 × 10−7* | 6.70* | ||||
| Pyrophosphoric acid | H4P2O7 | 1.2 × 10−1 | 0.91 | 7.9 × 10−3 | 2.10 | 2.0 × 10−7 | 6.70 | 4.8 × 10−10 | 9.32 |
| Resorcinol | C6H4(OH)2 | 4.8 × 10−10 | 9.32 | 7.9 × 10−12 | 11.1 | ||||
| Selenic acid | H2SeO4 | Strong | Strong | 2.0 × 10−2 | 1.7 | ||||
| Selenious acid | H2SeO3 | 2.4 × 10−3 | 2.62 | 4.8 × 10−9 | 8.32 | ||||
| Sulfuric acid | H2SO4 | Strong | Strong | 1.0 × 10−2 | 1.99 | ||||
| Sulfurous acid | H2SO3 | 1.4 × 10−2 | 1.85 | 6.3 × 10−8 | 7.2 | ||||
| meso-Tartaric acid | C4H6O6 | 6.8 × 10−4 | 3.17 | 1.2 × 10−5 | 4.91 | ||||
| Telluric acid | H2TeO4 | 2.1 × 10−8‡ | 7.68‡ | 1.0 × 10−11‡ | 11.0‡ | ||||
| Tellurous acid | H2TeO3 | 5.4 × 10−7 | 6.27 | 3.7 × 10−9 | 8.43 | ||||
| Trichloroacetic acid | CCl3CO2H | 2.2 × 10−1 | 0.66 | ||||||
| Trifluoroacetic acid | CF3CO2H | 3.0 × 10−1 | 0.52 | ||||||
| * Measured at 20°C, not 25°C. | |||||||||
| ‡ Measured at 18°C, not 25°C. | |||||||||
Source of data: CRC Handbook of Chemistry and Physics, 84th Edition (2004).