osmosis practical Flashcards
1
Q
why is percentage change used
A
allows comparison not all potatos have same mass
2
Q
what does x intercept on graph tell us
A
conc that is isotonic to solution tested
3
Q
why are potatos dabbed dry
A
to remove any excess water clinging to its surface
4
Q
what are the control variables of this experiement
A
volume of sucrose solution
size of potato chips length of time left in solution
dab each potato disc with paper towels
5
Q
what is a callibration curve
A
determines conc of unknown sample by comparing it to a set of standard values with known conc
6
Q
outline procedure of investigating osmosis using potato tissue
A
- make a serial dilution of 1M sucrose to produce 5 concentrations. Add 5cm3 to 5 different test tubes.
- cut potato chips into equal sized chips and weigh
- place a chip in each test tube and leave for 20 mins.
- take out, dab excess water and weigh again
- calculate percentage change in mass
