Acids and Bases

    Cards (19)

    • Strong Acid
      log10[H+]=-\log_{10}\left[H^+\right]=pHpH
    • Weak Acid
      HAH+HA\Leftrightarrow H^+++AA^-
      Ka =Ka\ = [H+][A][HA]\ \frac{\left[H^+\right]\left[A^-\right]}{\left[HA\right]}
      [H+]=\left[H^+\right]=[A]\left[A^-\right]
      Ka =Ka\ = [H+]2[HA]\ \frac{\left[H^+\right]^2}{\left[HA\right]}
      [H+]=\left[H^+\right]=Ka[HA]\sqrt{Ka\left[HA\right]}
      log10[H+]=-\log_{10}\left[H^+\right]=pHpH
    • Strong base
      Kw =Kw\ = [H+][OH]\ \left[H^+\right]\left[OH^-\right]
      [H+]=\left[H^+\right]=Kw[OH]\frac{Kw}{\left[OH^-\right]}
      log10[H+]=-\log_{10}\left[H^+\right]=pHpH
    • BUFFER: Weak acid + Salt 

      Ka =Ka\ = [H+][A][HA]\ \frac{\left[H^+\right]\left[A^-\right]}{\left[HA\right]}
      [H+]=\left[H^+\right]=Ka[HA][A]\frac{Ka\left[HA\right]}{\left[A^-\right]}
      log10[H+]=-\log_{10}\left[H^+\right]=pHpH
    • BUFFER: weak acid + strong base

      HA+HA+OHH2O+OH^-\rightarrow H_2O+AA^-
      Ka =Ka\ = [H+][A][HA]\ \frac{\left[H^+\right]\left[A^-\right]}{\left[HA\right]}
      [H+]=\left[H^+\right]=Ka[HA][A]\frac{Ka\left[HA\right]}{\left[A^-\right]}
      log10[H+]=-\log_{10}\left[H^+\right]=pHpH
    • acid - definition
      proton donor
    • base - definition
      proton acceptor
    • strong acid
      completely dissociates to ions in solution
      pH 0-1
    • weak acid
      slightly dissociates in solution
      pH 3-5
    • pH =
      log10[H+]-\log_{10}\left[H^+\right]
    • [H+]\left[H^+\right] = 

      10pH10^{-pH}
    • pure water
      H+H^+++OH  H2OOH^-\ \Leftrightarrow\ H_2O
    • equilibrium of water
      forwards reaction is endothermic
      favoured when temperature of water is increased
      more H+H^+produced - meaning water becomes more acidic as temperature increases
    • pKa =
      log10Ka-\log_{10}Ka
    • Ka =
      10pKa10^{-pKa}
    • methyl orange
      used in reactions with a more acidic neutralisation point
      orange in acids - turns yellow at neutralisation point
    • Phenolphthalein
      used in reaction with a more basic neutralisation point
      pink in alkalis - turns colourless at neutralisation point
    • Buffer calculations - Acid+base
      1. find number of moles in each species
      2. calculate concentration at equilibrium using total volume
      3. use Ka to find [H+]\left[H^+\right] and pH
    • Buffer calculations - Acid+salt
      1. find moles of salt
      2. use Ka to find pH
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