acids and bases

• strong acid

  completely dissociates in solution
• weak acid

  partially dissociates in soltion
• pH equation

  -$\log_{10}\left[H+\right]$
• [H+] equation

  10$^{-pH}$
• when pH changes by 1...

  [H+] changes by a factor of 10
• equation for a weak acid

  $Ka=$$\ \frac{\left[H+\right]\left[A-\right]}{\left[HA\right]}$
• pKa equation

  $pKa=$$-\log_{10}Ka$
• in a weak acid we can assume

  [H+]=[A-] therefore, $\frac{\left[H+\right]^2}{\left[HA\right]}$ so, [H+]= $\sqrt{Ka\left[HA\right]}$
• convert pKa into Ka

  Ka= $10^{-pKa}$
• ionic product of water

  Kw
• Kw equation

  [H+][OH-]
• at 298K, Kw equals

  $1\times10^{-14}$
• buffer solution

  solution that maintains an approximately constant pH on addition of small amounts of acid or base