To demonstrate osmosis

Question 1

What do you do first?

Answer 1

cut 2 equal lengths of visking tubing

Question 2

After cutting 2 pieces of visking tubing what do you do?

Answer 2

soften them by putting them under the tap water

Question 3

What do you add to each of the visking tubings?

Answer 3

place a volume of sucrose solution into one
as a control add distilled water into the other piece of visking tubing

Question 4

Once you have both visking tubings, one filled with water and one with sucrose solution what do you do?

Answer 4

tie them, dry them and find the mass

Question 5

Once both have been tied, dried and weighed what do you do?

Answer 5

place both tubings into a beaker of distilled water, supporting the top with a pencil

Question 6

What do you do after they have been placed in beaker?

Answer 6

after 20 mins, remove them and dry then reweigh

Question 7

What do you record after the 20 mins?

Answer 7

the difference in mass and note the “fulness” turgidity of each

Question 8

What are the 2 results/takeaways?

Answer 8

• visking tubing with the sucrose solution was fuller and increased in mass (water moved from a region of high water concentration to a region of low water concentration)
• mass of visking tubing with water did not change (isotonic)

Question 9

Definition of osmosis?

Answer 9

the movement of water molecules across a semi-permeable membrane from a region of high water concentration to a region of lowe water concentration

Question 10

Does osmosis require energy?, give a point.

Answer 10

no, it is passive transport

Question 11

In this experiment what is the semi-permeable membrane?

Answer 11

the visking tubing

Question 12

What do you use to weigh the visking tubings for mass (not weight)?

Answer 12

mass balance