The+Know+It+All

** The Chemistry Behind It All ** In my experiment, there are 4 main components that are going to be discussed which include: Hydrogen Peroxide, Exothermic Reactions, Decomposition Reactions and Catalysis. Each of these components are used daily in nature as well as industries and chemical laboratories.

Hydrogen Peroxide: Chemical formula of the common compound is H2O2, a colorless, syrupy liquid that is soluble in alcohols and ethers and is miscible in cold water. Hydrogen peroxide is a very strong oxidizing agent and is severely corrosive to the skin eyes and respiratory tract. Hydrogen peroxide is a common household product that can be purchased as 3% water solution, also sometimes called ten volume strength. It can be used as a disinfectant, antiseptic, and oxidizer. Hydrogen peroxide can be purchased for commercial use in many different concentrations. In my experiment I will be using 30% for which is only one of the several concentrations used, Hydrogen Peroxide is used on a large scale in bleaching industries and as a substitute for chlorine-based substances. It is also used to manufacture Sodium Perborate and Sodium Percarbonate, which are also bleaches used in laundries to wash dirt off these clothes.

Decompositions: A decomposition reaction is a type of reaction that breaks down a compound into two or more basic components (elements or compounds) The main formula for decomposition reactions is AB ➔ A + B. This is the complete opposite of synthesis. For “Genie in a Bottle”, the balanced formula of the decomposition reaction is: 2 H2O2 ➔ O2 +2 H2O Hydrogen peroxide is catalytically decomposed to form a cloud (in this experiment a dark grey cloud). Most decomposition reactions require the aid of a catalyst, heat source, or solvent. For the decomposition of Hydrogen Peroxide to happen, it will take quite some time to fully complete the reaction if no catalyst is added. With the addition of a catalyst being MnO2 the reaction happens almost instantaneously. Decomposition chemical reactions can be classified into three categories being catalytic, electrolytic and thermal. Catalytic reactions is where a catalyst is added to cause the reaction to happen faster. Electrolytic reactions is when an aqueous or molten solution is exposed to electrical currents, and thermal reactions is when heat or radiation is directly added to start the reaction. A decomposition reaction always involves the exchange of energy. The two classifications of energy exchange are exothermic and endothermic reactions which describe the way in which the chemical bonds of the substances are broken: endothermic: energy is absorbed in the experiment and exothermic: energy is released in the experiment.

Exothermic Reactions An exothermic reaction is a chemical reaction that releases energy in the form of heat. It is the opposite of an endothermic reaction that absorbs heat. It can be expressed in a chemical equation as reactants ➔ products + energy. During the reaction of “Genie in a Bottle” one should not stand over the bottle because this reaction is exothermic and steam forms very quickly and shoots out of the bottle. During demonstration, the bottle should not be held as the bottle becomes very hot after the manganese dioxide is added to the hydrogen peroxide. An exothermic reaction produces heat because the energy needed for the reaction to occur is less than the total energy released. In my experiment you are able to see that heat is released as the bottle that the experiment is conducted in shrinks a little bit because the plastic is heated enough to melt it. The breakdown of glucose during cellular respiration is an example of an exothermic reaction that occurs in everyday life.

Catalysis: Without a catalyst, the decomposition of H2O2 would take years to complete fully but when a catalyst is added, in this case MnO2, it speeds up the reaction so much that the reaction happens almost instantaneously. A catalyst increases the rate of a chemical reaction by lowering the reaction activation energy level which allows equilibrium to be reached faster. During the experiment the catalyst is not used up in the experiment which means it can be fully recovered at the end of the experiment. Catalysts are important in chemical laboratories as well as industries because they allow for the reactions to occur faster. Some reactions occur faster in the presence of an acid or a base. An example of this is the hydrolysis of esters in which the hydroxide ion reacts with the ester and in the end of the reaction, the net amount of hydroxide ion present is the same at the beginning and the end of the reaction. Therefore the base is a catalyst and not a reactant. An extremely important catalyst used in everyday life is enzymes, which are the most efficient catalyst found in nature. Without enzymes, many of the human body and other living organisms chemical reactions would not occur because they are so high-energy reactions that occur so slowly without the presence of enzymes, if at all. Enzymes can increase the rate of reaction by a factor of one billion or more.