RP3- Investigating water potential

Question 1

What is a serial dilution?

Answer 1

When you create a set of solutions that decrease in concentration by the same factor each time

Question 2

Why are serial dilutions useful?

Answer 2

Creating weak solutions is much easier as you do not have to measure out very small volumes of liquids

Question 3

-Use a 1.____ ____ to cut up 2.______ into identically sized chips about 1cm in diameter
-Divide the chips into groups of 3._____
-Measure the 4._____ of each group using a 5.______ _____
-Place one group into each of your 6._____ solutions
-Leave the chips in the solution for at least 7._____ minutes (making sure that they all have the same amount of time)
-Remove the chips and pat 8._____ gently with a paper towel
-9_____ each group again and record 10._____
-Calculate 11._____ _______ in mass for each group

Answer 3

1. Cork borer
2. Potatoes
3. 3
4. Mass
5. Mass balance
6. Sucrose
7. 20
8. Dry
9. Weigh
10. Results
11. Percentage change

Question 4

What will the results of the experiment be?

Answer 4

-The potato chips will gain mass as they have gained water via osmosis, In solutions with higher water potential than the chips
-Loose water in solutions with a lower water potential

Question 5

How do you produce a calibration curve?

Answer 5

Plotting percentage change in mass against the concentration of sucrose solution

Question 6

How do you read a calibration curve?

Answer 6

-The point the curve crosses the X axis where the percentage change in mass is 0 is the point the water potential of the sucrose solution is the same as the water potential of the potato cells