In the experiment, aluminum is added to a solution of water and copper(II) chloride. The Cl2 combines with Al and leaves a red, mushy copper behind; the water rises 38°C. The question is, where does the reaction get the activation energy from? I‘m thinking the water heated because of the energy released with the combining of Cl2 and Al, but.that‘s the reaction itself, isn‘t?Your thoughts.?
To make aluminum metal , which isn't found in nature as the raw element, you have to apply lots of electricity to win it from it's ores. Aluminum has lots of energy just sitting there. It actually is on par with the energy found in gasoline. For gasoline to burn all it needs is an oxidizer and a spark to initiate the reaction. Aluminum is a little tougher to initiate since a protective aluminum oxide layer quickly forms on the surface of the metal protecting it from further oxidation. But if you put it in combination with a reactant that allows it to get past that protective layer and give enough heat to start the reaction , aluminum ends up giving a spectacular amount of heat in going back to a lower energy form and getting back to being a compound. AlCl3 has much lower energy levels than aluminum metal, so that is the direction any reaction with aluminum takes. Aluminum is a very potent fuel that is always looking for an oxidizer. When you add the aluminum to the copper chloride the aluminum becomes oxidized by the chlorine and releases a tremendous amount of heat in the process. That is why the water heated up so much. There is a famous reaction using iron oxide and aluminum powder that is called thermite, and this reaction is so hot and strong it will burn a hole thru a sheet of steel. So instead of being so wordy, I should just say itthe activation energy is completely from the aluminum. The copper chloride just allows the aluminum to give it's electrons to with a great vigor and dissolves the aluminum oxide layer from the aluminum to allow it to react with the chlorine So you are rightthe energy is from the chlorine and aluminum
It provides intermediates that have lower activation energy to make than just doing the reaction in one step without the enzyme.
