Investigating the Effect of Concentration on Osmosis

Investigating the Effect of Concentration on Osmosis

Preliminary Investigation

The aim of the preliminary experiment was to find a suitable range to

collect our results. To find a suitable range we had to carry out the

experiment to see if there was a substantial change in the size and

weight of the potato chip after it had been placed in a 1 molar

glucose and another chip in distilled water.

At the beginning of the experiment we had to cut out potato chips of

equal length and similar shape. We obtained the potato chip by using a

cork borer; we made sure we cut off the edge with the skin on it, as

this would affect the results at the end. Using a scalpel we sliced

the cylindrical piece of potato into equal lengths, measured them and

then weighed them. These are classified as our initial results. Since

we had a boiling tube of glucose and distilled water, these were

measured to the same volume earlier using a measuring cylinder. These

two tubes were then placed into a water bath that was heated using a

Bunsen burner to a temperature between 25-40ËšC. The potato chips were

then placed into each tube and left in there for 30minutes. After

these 30 minutes the chips were weighed and then measured to see if

there was any change.

We used 50ml of glucose and distilled water and the temperature of the

water bath was at 30ËšC.

Results

Solution

Initial Length of Chip (cm)

Final Length of Chip (cm)

1 Molar Glucose Solution

2.8

2.6

Distilled Water

2.8

3.0

Conclusion

From the results we can see that the chips had changed in length; we

can now use the same measurements in the main experiment as in the

preliminary experiment. These measurements include the length,

diameter of chip and temperature etc. When the chip was in distilled

water the size had increased and in the one molar glucose solution we