1 / 31

Acids and Bases

Acids and Bases. Drill – 4/23/08. Write everything you know about acids and bases!. Drill – 4/30/08. Write the equation for the neutralization reaction between carbonic acid and calcium hydroxide. Properties of Acids (in aq solution). Sour taste Low pH Turn litmus paper red

yoshi
Download Presentation

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. Acids and Bases

  2. Drill – 4/23/08 • Write everything you know about acids and bases!

  3. Drill – 4/30/08 • Write the equation for the neutralization reaction between carbonic acid and calcium hydroxide.

  4. Properties of Acids (in aq solution) • Sour taste • Low pH • Turn litmus paper red • Conduct electrical current

  5. Properties of Bases (in aq solution) • Bitter taste • Slippery • High pH • Turn litmus paper blue • Conduct electrical current

  6. Arrhenius Definition Acid = substance that releases H+ ions in aq solution HCl  H+ + Cl- Base = substance that releases OH-ions in aq solution NaOH  Na+ + OH-

  7. Bronsted-Lowry Definition As more and more substances were determined to have acidic or basic properties, even some without obvious H+ or OH-, a new definition was needed. • Acid = proton donor • Base = proton acceptor

  8. Bronsted-Lowry Definition • Acid = proton donor H2O + HCl  H3O+1 + Cl-1

  9. Bronsted-Lowry Definition • Base = proton acceptor NH3 + H2O  NH4+ + OH–

  10. Acid-Base Reactions • Known as a neutralization reaction. Acids and bases will react with each other to form water and salt. HCl + NaOH  H2O + NaCl

  11. Day 2

  12. Acid Naming Overview Binary Start with hydro- Element End with –ic acid Tertiary “I ate something, and now I am sick” If anion ends in –ate then the acid ends in –ic If the anion ends in –ite then the acid ends in -ous

  13. Acids & Bases Review • Acid • substance that releases H+ ions in aq solution • Proton donor • Electron pair acceptor • Base • substance that releases OH-ions in aq solution • Proton acceptor • Electron pair donator

  14. Acid Strength A stronger acid will transfer MORE protons (H+) than a weak acid. It will create more hydronium ions (H30+) in water. Hydrochloric acid HCl + H20  H30+ + Cl- Acetic Acid CH3COOH + H20 H30+ + CH3COO- More dissociation! Less dissociation!

  15. How do we compare the strength of an acid or a base? We measure the amount of hydronium ions they create (acids) or the amount of hydroxide ions they create (bases)….using concentration.

  16. What is concentration? • Using molarity, it is a measure of moles of solute in liters of solution. • Concentration is measured in WATER!

  17. H2O is both an acid and a base Water is simultaneously donating and accepting protons!

  18. What are the ion concentrations in water? • The concentrations of H3O+ and OH- in pure water are each 1.0x10-7 mol/L at 25ºC. • Putting a symbol in brackets is used to signify the concentration. • [H30+] = 1.0x10-7 M • [OH-] = 1.0x10-7 M

  19. Ionization Constant of water, KW • KW = [H30+] [OH-] • KW = (1.0x10-7)(1.0x10-7) = 1.0x10-14

  20. With an increase in [H30+], some of the H30+ ions will react with the OH- ions, reducing [OH-] . [H30+][OH-] will still = 1.0x10-14 • Acids increase the [H30+] Whenever [H30+] is greater than [OH-], the solution is acidic. • Bases increase the [OH-] Whenever [OH-] is greater than [H30+], the solution is basic.

  21. Concentration values tend to be small…so we use a more convenient scale. pH!

  22. pH + pOH = 14 • pH – A measure of the acidity of a solution. It is the negative logarithm of the hydronium ion [H30+] concentration. pH = -log [H30+]

  23. pH + pOH = 14 • pOH – A measure of how basic a solution is. It is the negative logarithm of the hydroxide [OH-] concentration. pOH = -log [OH-]

  24. The logarithm base 10 of a number x is the power to which 10 must be raised in order to equal x. • Log 10 x = ? Log 100 = ? • 10? = x 10 ? = 100

  25. Remember, our concentrations are SMALL. So we are going to be dealing with decimals… • Log 10 x = ? Log .001 = ? • 10? = x 10 ? = .001

  26. [H+] = 1.00 x 10-3 = 0.001 pH = -log [H+] pH = -log (1.00 x 10-3) pH = 3 To determine pH from a concentration where 1 is the only digit, write the concentration in scientific notation. The exponent will be the pH.

  27. For a base, you do the same thing except remember that you are solving for pOH first…

More Related