Naked Egg Experiment
DAY 1 BUBBLES OF CARBON DIOXIDE BEGIN TO FORM ON THE EGG SHELL.
DAY 7 A TRANSLUCENT EGG IS LEFT AFTER THE SHELL HAS DISSOLVED.
Here is a
classic experiment with eggs. If you soak a raw egg in vinegar,
over the course of time, the vinegar will dissolve the eggshell.
What you’re left with is the egg’s translucent membrane to protect
the egg. Since the shell is made up mostly of calcium carbonate.--
it contains calcium carbonate (94%), magnesium carbonate (1%),
calcium phosphate (1%), and 4% organic matter-- vinegar which
contains acetic acid will dissolve the shell.
egg in a tall glass or jar and cover the egg with vinegar. Wait
a few minutes a look at the jar. You should see bubbles forming
on the egg. Leave
the egg in the vinegar for a full 24 hours in the refrigerator.
After the 24 hours, carefully pour the old vinegar down the drain
and cover the egg with fresh vinegar. Place the glass with the
vinegar and egg back in the refrigerator for a full week. One
week later pour off the vinegar and very carefully rinse the egg
with water. The egg looks translucent because the outside shell
is gone. Notice that some
of the vinegar has permeated through the egg's membrane and caused
the egg to get a little bigger.
The egg shell
is composed of calcium carbonate (CaCO3). When calcium carbonate
comes in contact with vinegar which contains acetic acid (CH3CO2H)
a chemical reaction occurs.
thing that happens is that the carbonate (CO3--)
part of calcium carbonate is protonated by acetic acid to make
carbonic acid (H2CO3).
this , the calcium and acetate from calcium acetate.
+ CaCO3 = H2CO3 + Ca(CH3COO)2.
In the next
step, the carbonic acid breaks down to form carbon dioxide and
water, H2CO3 = H2O + CO2.
reaction is just to sum of the two reactions given,
+ CaCO3 = H2O + CO2 + Ca(CH3COO)2.
2CH3COOH(l) Ca(CH3COO)2(s) +
H2O(l) + CO2(g) Water and excess vinegar
evaporate upon standing. Carbon dioxide (a gas) is released into
the air during the reaction.
dissolve the eggshell, the egg is surrounded by a membrane. (Actually,
it’s two membranes, but they are held tightly together). To get
a better idea of see
Anatomy of an Egg.
a naked egg look and feel like? See this mpg
from University of Iowa.
Where to go
Here are some
excellent classroom experiments using naked eggs that demonstrate