There will be 6 concentrations and each concentration will be done three times to
ensure the accuracy of the results. Then I will measure them and make them all 3cm
long and weigh 3.8g. Then I will put them all in test tubes with a glucose solution with
six different concentrations of glucose. The bungs will be placed in the test tube and
the test tubes will be left for 24 hours. I will be wearing safety goggles when doing the
experiment and make sure not to break any glass. The only variable will be the
concentration of the solution. I could have also used the temperature as the variable
but for this experiment it will stay the same. The blunt cork borer may damage the
cells around the outside of the potato tuber, there is nothing I can do to change this
but it should be the same for all the potato tubers.
Prediction/Hypothesis: I predict that the when the concentration of the glucose
solution and the potato are equal the potato will not change in length or weight. The
way osmosis works, nothing should happen when the concentrations are the same. I
predict that the glucose concentration of the potato cells will be about 0.4m - 0.5m. I
found this in past work.
Results:
Sugar
Concentration
Mass (g)
Average
Mass (g)
Difference
(g)
Length (cm)
Average
Length (cm)
Difference
(cm)
4.4
3.2
Distilled Water
4.3
4.3
+0.5
3.5
3.3
+0.3
4.1
3.2
3.9
3.3
0.2 M
3.8
3.9
+0.1
3.2
3.26
+0.26
4.1
3.3
4.0
3.1
0.4 M
3.6
3.8
0
3.4
3.26
+0.26
3.9
3.3
3.0
3.0
0.6 M
3.1
3.1
-0.7
2.6
2.76
-0.24
3.3
2.7
2.8
3.0
0.8 M
2.6
2.6
-1.1
2.8
2.8
-0.2
2.5
2.6
2.4
2.7
1.0 M
2.4
2.4
-1.3
2.7
2.76
-0.24
2.3
2.9
Conclusion: This results table shows the glucose concentration of the potato is around
0.4 M. This is because there was the least change in Mass and Length at 0.4M. This
proves my prediction to be correct. The experiment works because of the way
osmosis works. The experiment would still work if there was no sugar in the potato.
This experiment could be used in other plants as well to find the concentration of
sugar in them. The experiment was fair enough to give good results but could have
been done in a more controlled way or place. None of the results were extremely
anomalous but if the test went perfectly the would have gone in a straight line on a
graph. The results of both Length and Mass for 0.4M were the most anomalous.