What+type+of+reaction+is+it?

A main section of our ISU, is to research and explain which type of reaction occurs in our individual experiment. Most students had decomposition reactions, but I found that my experiment was unique. My experiment could be classified as two different types of reactions, neither of which are decomposition. The first type of reaction is osmosis. The second is a single displacement reaction. In this essay I will explain what these reactions are, and how they occur in my specific project.The definition of a single displacement reaction is a chemical reaction, in which one element trades places with another element in a compound, to form a new free element and a new compound. Generally, the reaction looks like this **A + BC ---> AC + B**. For this to occur, element **A** would have to be more reactive than element **B**. This requires breaking of bonds and using a large amount of energy to rearrange the atoms.
 * __What type of reaction occurs?__**

In the first step of my experiment, I place an egg in a beaker filled with vinegar. When the egg is left in the vinegar for an extended amount of time, 2 or 3 days, the shell off the egg is completely dissolved. The egg is left with just a thin transparent membrane, which is very weak and permeable to water. When you look into the beaker, you can see remnants of the shell, floating on top of the vinegar that is remaining. The shell of the egg has gone through a single displacement reaction with the vinegar. The equation is:


 * CaCO3(s) + 2HC2H3O2(aq) > Ca(C2H3O2)2(aq) + H2O(l) + CO2(g) **

The shell of the egg is mostly made of calcium carbonate, and another name for vinegar is acetic acid. The acetic acid dissolves the shell right off the egg. The calcium in the eggshell is combined with the vinegar, while the Carbonate gets broken down into carbon dioxide gas and an oxygen forms water with two hydrogens from the acetic acid. This is how a single displacement reaction occurs in this experiment. Calcium is more reactive than hydrogen, so it is easier for the calcium to break apart the hydrogens to join onto the acetic acid. After this first step of the reaction we are left with a mixture of vinegar, and calcium, but we are also left with a shell-less egg. The egg itself is made of a permeable membrane surrounding, a complex liquid solution of proteins, lipids, carbohydrates and salts. The next step of this experiment requires osmosis to occur. When I first started this project I was unsure where I wanted to go with it. So I will explain all the different ways I saw osmosis work, throughout my observations.

Osmosis is defined as the movement of water molecules from an area of higher concentration to a lower concentration. If the concentration inside the membrane is lower than the concentration outside the membrane, it is likely to swell, and could possibly burst, due to water molecules rushing in to try to make an equilibrium. If the concentration inside the membrane is higher than the outside, water will rush out through the membrane and the cell could possibly shrivel. The first time I did this experiment I placed two shell-less eggs into a beaker filled with water and green food colouring, and I placed one egg with a shell into a beaker of corn syrup. I left each beaker to sit for approximately twenty four hours. I was amazed by the results that I found. The eggs that were left in the food coloured water had changed to the colour of the water and the size of the egg increased drastically. The egg that was left in corn syrup was shrivelled and all that was left inside the egg was the yolk. I placed one of the green eggs back into a clean beaker of distilled water, and left it for a day. When I went to check on my egg I found that the water had turned almost completely green.

The changes of size and colour of the eggs in this case, are all due to osmosis. Since corn syrup is thicker than the contents of the egg, everything inside the egg (except the yolk) rushed out into the area around it and the sugars in the corn syrup were to thick to pass through the membrane. Causing the egg to shrivel. The eggs soaked in water absorbed the water through the membrane because the water was thinner than the contents of the egg. This caused the eggs to swell and take on the colour of the water.

When the eggs were cooked, no chemical reaction occurred. They were heated to a point that they could be eaten. The eggs were cooked two different ways. For the first egg, I gently broke the membrane over the frying pan and the egg spilled out. There was a large amount of water in the egg, due to osmosis. This egg took a long time to cook. All the water had to be absorbed before the egg could be fully cooked. When it was cooked, it was edible although tasted quite bitter. The second way the eggs were cooked was by just setting the egg on the frying pan. After a few minutes, the membrane on the egg did break. The yolk was still intact, and there was less water in the egg. Although this way there was not much egg left, it was only yolk.

I conclude my ISU essay by stating, that it is very possible to create and cook green eggs, although I do not recommend eating them because they taste very awful.