lab report
Potato Osmosis
Biology SL - ATh
INVESTIGATION
“Potato Osmosis”
INTRODUCTION
Osmosis is a process that occurs at a cellular level that entails the spontaneous net movement of water through a semi-permeable membrane from a region of low solute concentration to an area of high solute concentration in order to equalize the level of water in each region.
Involved in this process are hypotonic, hypertonic and isotonic solutions. A hypotonic solution is one with a lower osmotic pressure, indicating that the net movement of water moves into the said solution whereas a hypertonic solution is one with a higher osmotic pressure, thus the net movement of water will be leaving the hypertonic solution. Lastly, an isotonic solution entails no net movement of water across a semi-permeable membrane as the two substances involved display osmotic equilibrium.
AIM
To observe the effect of solutions different levels of NaCl concentration on potatoes, considering the process of osmosis
METHOD
(see ‘Potato Osmosis’ – exercise document)
Table of NaCl-H2O Dilutions
NaCl Solution / ml ±1
100
75
50
25
0
Distilled H2O/ ml ±1
0
25
50
75
100
NaCl Concentration/M
1.00
0.75
0.50
0.25
0.00
Official Timeframe of Experiment
Insertion Time: 29 November, 2007 – 8:54 am
Extraction Time: 30 November, 2007 – 9:40 am
Legend for Potato Differentiation
Potato
Mark
Potato 1
Vertical line
Potato 2
Horizontal Line
Potato 3
Notch
DATA COLLECTION
(Fig. 1) Diagram demonstrating the correct preparation of a potato – cylindrical strips marked according to the legend
Potato Osmosis
Biology SL - ATh
Raw Data Table – Mass and Lengths of Potato Strips – Pre- & Post-Experiment
NaCl
Potato
Initial Mass/
Mass after
Initial Length
Concentration/M Samples g±0.01 Solution /
/mm±1
g±0.01
1.00
Potato 1
1.93
1.42
40
Potato 2
1.88
1.31
40
Potato 3
2.02
1.56
40
0.75
Potato 1
1.98
1.42
40
Potato 2
2.09
1.46
40
Potato 3
Biology SL - ATh
INVESTIGATION
“Potato Osmosis”
INTRODUCTION
Osmosis is a process that occurs at a cellular level that entails the spontaneous net movement of water through a semi-permeable membrane from a region of low solute concentration to an area of high solute concentration in order to equalize the level of water in each region.
Involved in this process are hypotonic, hypertonic and isotonic solutions. A hypotonic solution is one with a lower osmotic pressure, indicating that the net movement of water moves into the said solution whereas a hypertonic solution is one with a higher osmotic pressure, thus the net movement of water will be leaving the hypertonic solution. Lastly, an isotonic solution entails no net movement of water across a semi-permeable membrane as the two substances involved display osmotic equilibrium.
AIM
To observe the effect of solutions different levels of NaCl concentration on potatoes, considering the process of osmosis
METHOD
(see ‘Potato Osmosis’ – exercise document)
Table of NaCl-H2O Dilutions
NaCl Solution / ml ±1
100
75
50
25
0
Distilled H2O/ ml ±1
0
25
50
75
100
NaCl Concentration/M
1.00
0.75
0.50
0.25
0.00
Official Timeframe of Experiment
Insertion Time: 29 November, 2007 – 8:54 am
Extraction Time: 30 November, 2007 – 9:40 am
Legend for Potato Differentiation
Potato
Mark
Potato 1
Vertical line
Potato 2
Horizontal Line
Potato 3
Notch
DATA COLLECTION
(Fig. 1) Diagram demonstrating the correct preparation of a potato – cylindrical strips marked according to the legend
Potato Osmosis
Biology SL - ATh
Raw Data Table – Mass and Lengths of Potato Strips – Pre- & Post-Experiment
NaCl
Potato
Initial Mass/
Mass after
Initial Length
Concentration/M Samples g±0.01 Solution /
/mm±1
g±0.01
1.00
Potato 1
1.93
1.42
40
Potato 2
1.88
1.31
40
Potato 3
2.02
1.56
40
0.75
Potato 1
1.98
1.42
40
Potato 2
2.09
1.46
40
Potato 3