Ben Williams
2-16-12
Mr. Emmi
7th Hour
Gummy Bear in
tap water
Before Water
After Water
After Salt Water
Gummy Bear in
Distilled Water
Length
Gummy Bear Lab
Width
1cm
1.75cm
0.5cm
Length
1cm
1.75cm
1cm
Width
2cm
3.5cm
1.5cm
Height
2cm cubed
10.72cm cubed
0.75cm cubed
Volume
Before Water
After Water
After Salt Water
1cm
2cm
0.5cm
1cm
1.5cm
0.5cm
2cm
4cm
2cm
2cm cubed
12cm cubed
0.5cm cubed
Height
Volume
A. When the bear was put into the distilled water, it grew significantly, and
ended up larger than the Tap Water bear. This is because a type of diffusion
called “osmosis” happens commonly when water makes contact with a
permeable membrane and one side of this membrane contains less water
than the other. Osmosis forces the water level to balance out by moving
through the membrane. Since distilled water is pure water with no
impurities, more water can fill into the bear than plain Tap Water.
B. When the bear was placed into Tap Water, it followed almost the exact
process that the distilled water bear followed, except that the tap water
contains more impurities, causing less water to flow in. Again, osmosis takes
effect and the bear fills with water, but this time, impurities as well. These
impurities fill space that could be filled with water, so less water exists in the
bear.
C. When the bears, both tap water as well as the distilled water, were
submerged in salt water, they both significantly shrank. This may be caused
by the fact that salt immediately tries to bond with water, explaining the
change in water level and the ring of salt where the water used to be. The salt
first went to a large source of water, being the bear, and taking the water
from it, giving it it’s new small size.
D. If these small bears were now, after being submerged in salt water, to be put
into distilled water for 24 hours more, I predict then would grow to be a
fairly large size again. This is because they are now in a more water filled
environment, and would absorb this water to a size between their original
size and the size they assumed when they were put in the distilled water
previously.
Bears
% Change in Water
% Change in Salt Water
Tap Water Bear
525% Increase
93% Decrease
Distilled Water Bear
600%
95.83% Decrease
In our Gummy Bear experiment, we have concluded that gummy bears have a
permeable membrane out side of it, allowing water to freely flow in and out, also
known as the process of diffusion or osmosis. We have also discovered that the bear
grows significantly more in distilled water, which is free of impurities, than tap
water, which includes impurities. This does cause a higher percent of shrinkage
when put in the salt water, because they shrink to close to the same final size.
Osmosis takes place in all of these portions, whether it is filling the bear with water,
or removing it to cover for the amount of saturated water existing around it. If we
were to put the bears into distilled water now, I hypothesize that they would expand
to a volume of some where in between the original volume and the volume it had
after 24 hours of sitting in distilled water. Overall, we see that the bear has wide
capabilities of expanding from large to small as shown in the graph and in the
charts, and that the bears have a very permeable membrane that water easily passes
through.