Osmosis In Visking Tubing And potato

Question 1

How is osmosis measured ?

Answer 1

• by measuring the change in length or mass of plant tissue or model cells, using Visking tubing

Question 2

What equipment is used to cut the potato?

Answer 2

A borer

Question 3

Conclusion

Answer 3

The potato cell membrane acts as the semi-permeable membrane. There is a difference in the concentration of water in the cell and the concentration of water in the solution

Question 4

Suggest two reasons why it’s more accurate to use mass rather than length of potato

Answer 4

• Larger changes are observed from the start to 24 hours later
• easier to estimate the concentration of sucrose that could have the same concentration as the potato

Question 5

Process of visking tubing (5)

Answer 5

• Cut equal lengths of Visking tubing.
• Add 5% sucrose solution to a section of visking tubing, ensuring the tubing is tied securely at each end
• dry the outside of the tubing if necessary and weigh the tubing and contents
• or measure the circumference of the filled tubing using string.
• Add The visking tubing to a beaker of water and leave for an hour

Question 6

Controlled variables

Answer 6

• Equal lengths of Visking tubing / sizes of potato cylinders
• Same Volume of water

Question 7

Dependant variable

Answer 7

• Mass of plant tissue / visking tubing

Question 8

Independent variable

Answer 8

• Concentration of sucrose