Prepare and show the production of alchohal by Yeast (And presence of ethanol)

Question 1

Method of procuring alchohal by yeast

Answer 1

1. Boil glucose solution in a conical flask (anaerobic conditions)
2. Allow solution to cool and add dried yeast.
3. Cover solution with a layer of oil.
4. Place fermentation lock containing limewater in a conical flask.
5. Place Conical flask and fermentation lock into a water bath overnight.

*control is same experiment without Yeast.

Question 2

Results of alcohol

Answer 2

1. Limewater turns milky.
2. Bubbling occurs in conical flask

Question 3

Iodoform test to show presence of ethanol

Answer 3

1. Filter solution (to remove yeast cells)
2. Add potassium iodide to the filtrate.
3. Add sodium hypochlorite solution.
4. Heat and then allow to cool
5. Yellow crystals will form if ethanol is present