osmosis practical

Question 1

why is percentage change used

Answer 1

allows comparison not all potatos have same mass

Question 2

what does x intercept on graph tell us

Answer 2

conc that is isotonic to solution tested

Question 3

why are potatos dabbed dry

Answer 3

to remove any excess water clinging to its surface

Question 4

what are the control variables of this experiement

Answer 4

volume of sucrose solution
size of potato chips length of time left in solution
dab each potato disc with paper towels

Question 5

what is a callibration curve

Answer 5

determines conc of unknown sample by comparing it to a set of standard values with known conc

Question 6

outline procedure of investigating osmosis using potato tissue

Answer 6

1. make a serial dilution of 1M sucrose to produce 5 concentrations. Add 5cm3 to 5 different test tubes.
2. cut potato chips into equal sized chips and weigh
3. place a chip in each test tube and leave for 20 mins.
4. take out, dab excess water and weigh again
5. calculate percentage change in mass