Esterification Reaction between Alcohol and Carboxylic Acid

Materials Required:

Ethanoic acid (3 mL), ethanol (3 mL), a few drops of conc. H2SO4, distilled water, sodium hydrogen carbonate 100ml solution, thermometer (– 10 oC to 110 oC), a test tube, a cork, measuring cylinder (10 mL), a beaker (250 mL), burner, tripod stand, clapping stand, and a wire gauge and dropper.

The Procedure:

Real Lab Procedure

  • Take a clean test tube that is kept in the test tube stand and add 3 mL ethanoic acid using a measuring cylinder. 
  • In the test tube containing the ethanoic acid, add 3 mL of ethanol to it using a measuring cylinder.
  • Add four to five drops of conc. H2SO4 ( Sulphuric acid) to the reaction mixture using a dropper.
  • Put a cork loosely over the mouth of the test tube.  
  • Take about 150 mL water in the beaker. Heat it to about 60 °C.  
  • Put the test tube in the warm water and use the tripod stand to make the test tube stand straight in the beaker. 
  • Dip the thermometer in the beaker thermometer to maintain the temperature of the reaction mixture.  
  • First unclamp the test tube from the stand and shake the reaction mixture at 40-degree Celsius C and 60 degrees Celsius occasionally.  
  • Pour the reaction mixture in the test tube into new beaker containing an aqueous solution of sodium hydrogen carbonate solution. 
  • Fan the liberated vapors of ester, formed with your hand gently towards your nose and smell.  

Simulator Procedure

  • Add 3ml of ethanol into test tube containing 3 mL ethanoic acid using measuring cylinder 
  • Using the dropper add the conc. H2SO4  
  • Put the cork over the mouth of the test tube. 
  • Click on the NEXT button. 
  • Drag the test tubes towards the beaker containing water. 
  • Drag a thermometer into the test tube to maintain the temperature. 
  • Click on the burner knob to heat the water in the beaker. 
  • Click on the burner knob to turn off the flame. 
  • Shake the test tube occasionally at 40oC and 60oC. 
  • Take out the cork from the mouth of the test tube 
  • Pour the reaction mixture in the test tube into new beaker containing an aqueous solution of sodium hydrogen carbonate solution.  

Result and Discussion:

  • Comment on the difference in odours of ethanoic acid, ethanol and ester. 
  • Esters are formed when -OH of carboxylic acid are replaced by -OR (here R represent an alkyl group). In this reaction conc. H2SO4  is used as a catalyst. 

Precautions:

  • Be careful while using conc. H2SO4 
  • The organic compounds are extremely volatile and alcohol is combustible so never heat it directly on a flame.  
  • Always use water bath for heating the reaction mixture.