acids/bases

• Bases have a pH greater than 7 and turn red litmus paper blue.
• Acids are sour-tasting compounds that release hydrogen ions when dissolved in water.
• Acids are sour
• Bases are bitter and slippery
• Acids create hydrogen bubbles
• For strong acid solutions

  pH will equal the concentration of the solution multiplied by the number of H+ ions produced by 1 molecule of the acid
• To calculate concentrations from pOH

  OH-] = antilog (-pOH)
• To calculate concentrations from pH


  [H+] = antilog (-pH)
• pH + pOH =


  14
• pOH

  is used to express concentration of hydroxide ions

  pOH = - log [OH-]

  pOH < 7 is basic

  pOH > 7 is acidic

  pOH = 7 neutral
• pH

  is an easier way to express H+ ion concentration.

  pH = - log [H+]

  pH < 7 means acidic solution

  pH > 7 means basic solution

  pH = 7 means neutral solution

  pH can never be less than 0 or greater than 14
• We can use Kw to calculate unknown

  [ ] of ions
• If Kw never changes, that means:

  Increasing H+ will cause OH- to decrease

  Increasing OH- will cause H+ to decrease.
• Kw=


  (ion product constant for water) is equal to 1 x 10-14 .
• Kb=


  (base ionization constant) .
• Weak bases ionize partially :


  to form CA and hydroxide ions.
• Strong bases ionize completely :

  into metal ions and hydroxide ions.
• Ka=


  (acid ionization constant.
• Weak acids


  Ionize partially
• Equilibrium (strong acids)


  Will favor the right side .
• Strong acids


  With ionize completely .
• Polyprotic acids


  can donate more than one H+

  All will ionize (donate H+) in STEPS, not all at .
• Monoprotic


  - can donate only one H+ ion per molecule.
• Water is amphoteric


  can act as an acid OR a base, depending on the substance dissolved in it.
• Bases become :

  Conjugate acids .
• Acids become:


  Conjugate Base
• Acids and bases acting in the reverse direction (on the right of the arrow) :


  called conjugates.
• Bases:

  are H+ acceptors (gain a H+ ion).
• Acids:


  are H+ donors (lose a H+ ion).
• Bases:

  have the OH group and create the OH- ion in aq solutions.
• Acids:


  have hydrogen and create the H+ ion in aq solutions.
• Water is neutral because the H2O :

  self-ionizes into one + and one - ion.
• Basic solutions :

  have more hydroxide ions than hydrogen ions.
• Acidic solutions :

  have more hydrogen ions than hydroxide ions.
• "neutral"


  does NOT mean the absence of ions; it means the amounts of + and - ions are equal.
• Litmus paper -


  indicates the type of solution based on a change in color.
• Both acid and base aqueous solutions conduct:

  ELECTRICITY
• Acids:


  can react with metals to make hydrogen gas and can react with carbonates to make carbon dioxide.
• BASES:


  cause a bitter taste and are slippery as solids and liquids.
• ACIDS :

  CAUSE FOODS TO TASTE SOUR OR TART .