pratical 14

• Measure a fixed volume of sugar solution and add to the boiling tube.
• Place the boiling tube into a water bath for 5 minutes.
• Weigh a fixed mass of yeast and add to the boiling tube.
• Add a small quantity of oil to cover the top of the solution to prevent air from entering the solution.
• Use a delivery tube and a bung to connect the boiling tube to another test tube half-filled with limewater.
• Start timing immediately.
• Count the number of bubbles produced in 1 minute and record in a table as seen below.
• Repeat steps 1-6 twice and take a mean number of bubbles.
• Repeat steps 1-7 at a range of different water bath temperatures.