Acidic Environment

Acidic Environment

1. 1. Indicators

   • Classification of common substances
   • Litmus, phenolphthalein, methyl orange & bromothymol blue
   • Everyday uses of indicators
   • Range of colour changes
   • EXPERIMENT: Prepare & test a natural indicator
   • EXPERIMENT: Classifying household substances

2. 2. Acidic Oxides

   • Oxides of non-metals acting as acids
   • Position of acidic/basic oxides in Periodic Table
   • Le Chatelier's principle
     • Factors which affect equilibrium
   • Solubility of carbon dioxide in water
   • Natural & industrial sources of SO2 and NOx
     • Environmental impact
     • Evidence of increase in acidic oxides in the atmosphere
   • Calculating volume of gases
     • EXPERIMENT: Decarbonating soft drink
   • Formation & effects of acid rain

3. 3. Acids occur everywhere

   • Acids = proton donors + ionisation of acids in water
   • Acetic, citric, HCl & sulfuric acid
   • Use of pH scale
   • Calculating pH
     • EXPERIMENT: Use of pH meters
   • Strengths of equal concentrations of acids in terms of degree of ionisation
     • EXPERIMENT: Calculating pH
   • Difference between strong & weak acid
   • Use of acids as food additives
   • Naturally occurring acids & bases

4. 4. History of acids

   • Lavoisier, Davy & Arrhenius
   • Bronsted-Lowry theory
   • Conjugate acids & bases
   • Salts which form acidic, basic or neutral solutions
     • EXPERIMENT: Calculating pH of salt solutions
   • Amphiprotic substances
   • Neutralisation = exothermic reaction
   • Correct technique for titrations
     • EXPERIMENT: Titrations + Preparing standard solutions
   • Effect of buffers
   • Use of neutralisation reactions as a safety measure

5. 5. Esterification

   • Functional groups of alkanol & alkanoic acids
   • Difference in m.p. & b.p. of alkanols & alkanoic acids
   • Esterification = reaction between an acid & alkanol
     • EXPERIMENT: Prepare an ester
   • Purpose of using acid as a catalyst
   • Need for refluxing
   • Examples of occurrence, production & uses of esters
     • Uses of esters as flavours & perfumes