1 / 15

HL Acids and Bases

HL Acids and Bases. Review for test. What are the 3 theories of acids and bases? Lavoisier Arrhenius Br Ø nsted -Lowry Lewis. HL Acids and bases. What are conjugate pairs? They differ by one proton or a H+. HL Acids and bases. What are the basic properties of acids and bases?

ranger
Télécharger la présentation

HL Acids and Bases

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. HL Acids and Bases Review for test

  2. What are the 3 theories of acids and bases? • Lavoisier • Arrhenius • BrØnsted-Lowry • Lewis HL Acids and bases

  3. What are conjugate pairs? • They differ by one proton or a H+. HL Acids and bases

  4. What are the basic properties of acids and bases? • React differently with indicators. • Acids react with metals, bases, carbonates. • They can be strong or weak. • Low pH or high pH. HL Acids and bases

  5. How do we use pH and properties of water in calculations? • pH = -log[H+] pOH = -log[OH-] • Kw = [H+] [OH-] • Kw has different values depending on temperature. • The concentrations are inversely related. • What is the pH of blood that has 4.60 x 10-8 H+ concentration at 25º C? (Kw = 1x10-14) HL Acids and bases

  6. How do pH and pOH relate? • pH + pOH = 14.00 at 25º C. • pH and pOH can be found from concentrations of strong acids and bases • Ka is acid dissociation constant. • How is it different for strong and weak? HL Acids and bases

  7. What is the Ka of .01 M ethanoic acid with a pH of 3.4? • pH = -log [H+] • .01 – 4 x10-4 • Acid dissociation equation. • How about .75 M with a Ka of 1.8 x 10-5 has what pH? HL Acids and bases

  8. What are pKa and pKb? • These are negative logs of base 10 of Ka and Kb. • This gives positive values with no units. • Ka and pKa have inverse relationship (b also). • A change in one unit of pKa represents 10 the change in Ka (b also). • They are all still temperature related. HL Acids and bases

  9. What is the relationship between Ka and Kb and pKa and pKb? • Ka x Kb = [H+] [OH-] = Kw • pKa + pKb = pKw • pKa + pKb = 14 at 25C HL Acids and bases

  10. What are buffer solutions? • Buffers resist change in pH (pOH) with addition of small amounts of acid or base. • Acidic buffers are a weak acid and salt of weak acid and strong base. • Basic buffers are a weak base and salt of weak base with a strong acid. • They act on LeChatlier’sprinciple. HL Acids and bases

  11. How do we find the pH of a buffer solution? • Henderson-Hasselbalch equation • pH = pKa + log [salt]/[acid] • pOH = pKb + log [salt]/[base] • What is the pH of 25 mL of ethanoic acid and sodium ethanote with a Ka of 1.8 x 10-5? HL Acids and bases

  12. What is salt hydrolysis? • All acid base reactions create salts (cation from base and anion from acid). • If there is a weak acid, the anion is a strong enough that can it hydrolyse water releasing OH. • If there is a weak base and the cation is a nonmetal, it is able to hydrolyse water relasing H. • If the metal is small with a decent charge density, it acts like a ligand complex and takes OH out of the solution. (Be, Al, Fe) HL Acids and bases

  13. What is titration? • It is a controlled acid base neutralization reaction trying to find the equivalence point. • This is used to find the concentration of an unknown with a known amount of a known concentration. HL Acids and bases

  14. What are titration curves? HL Acids and bases

  15. What are indicators? • They are sensitive to changes in pH. • They change colors at specific pH’s. • Change color when pKa = pH. • This is the end point. • Used to find equivalence points in titrations. HL Acids and bases

More Related