Water potential of potato

Question 1

Briefly outline how you would calculate the water potential of a potato chip

Answer 1

1) Serial dilution of different concentrations of sucrose solution
2) Cut and dry potato chips
3) Weigh potato chips + record its mass
4) Put bungs in the tubes and leave
5) Remove chips, dry, and re-weigh
6) Calculate the percentage change in mass
7) Plot a graph
8) Work out water potential using a calibration table

Question 2

What graph should be plotted when working out the water potential of a potato chip?

Answer 2

Percentage change in mass against concentration of sucrose solution

Question 3

Why do we put bungs in the tubes?

Answer 3

To prevent water evaporating

Question 4

Why do we dry potato chips in the same way?

Answer 4

To ensure excess water isn’t included in the weight

Question 5

Benefit of measuring the percentage change in mass?

Answer 5

More comparable