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Chapter 6, Lesson 7 Multimedia

Thermite Reaction

The strongly exothermic thermite reaction, in which iron oxide and aluminum react to produce elemental iron and aluminum oxide.

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  • Iron oxide, aluminum, and a catalyst are placed in a flower pot.
  • The reaction is extremely exothermic resulting in molten iron and aluminum dripping into sand below the flower pot. The demonstration shown in this video is very dangerous. Do not attempt to perform this demonstration.

Nitrogen Triiodide Reaction

Solid nitrogen triodide crystals violently decompose into nitorgen gas and iodine vapor when touch only slightly with a feather.

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The nitrogen triiodide is so unstable that the slightest touch will cause it to decompose in an exothermic reaction. The demonstration shown in this video is very dangerous. Do not attempt to perform this demonstration.

White Phosphorous Reaction

A solution of phosphorous dissolved in carbon disulfide is taken from a flask using an eyedropper and placed on filter paper. As the solvent evaporates, the phosophorous reacts with oxygen in the air and combusts, setting the paper on fire.

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  • White phosphorous dissolved in a solvent is dripped onto a piece of paper.
  • When the solvent evaporates, the phosphorous combines with oxygen in an exothermic reaction. The demonstration shown in this video is very dangerous. Do not attempt to perform this demonstration.

Methane Combustion Energy

This animation shows how the combustion of methane is an exothermic reaction. Small energy arrows pointing into the reactants and larger energy arrows pointing out of the products show that overall the reaction releases energy.

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The combustion of methane is an example of an exothermic reaction. More energy is released when the bonds in the products are formed than is used to break the bonds of the reactants. This is shown by larger energy arrows coming out of the products and smaller energy arrows going into the reactants.

Baking Soda and Calcium Chloride Reaction

The chemical equation for the reaction between baking soda and calcium chloride. Calcium chloride and sodium bicarbonate react to yield calcium carbonate, sodium chloride, water, and carbon dioxide.
  • In this reaction, the temperature goes up so it is exothermic.
  • In an exothermic reaction, more energy is released when bonds in the products are formed than is used to break the bonds in the reactants.

Baking Soda and Vinegar Reaction

  • In this reaction, the temperature goes down so it is endothermic.
  • In an endothermic reaction, more energy goes into breaking the bonds of the reactants than is released when the bonds in the products are formed.

Endothermic Reaction

Energy is required to break bonds, and energy is released as new bonds are formed. In an endothermic reaction, more energy is required to break the bonds in the reactants than is released when the bonds are formed in the products.

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  • Energy is used to break the bonds of the reactants.
  • Energy is released when the bonds of the products are formed.
  • Since more energy is absorbed when the bonds are broken than is released when new bonds are formed, the reaction is endothermic and the temperature goes down.

Exothermic Reaction

Energy is required to break bonds, and energy is released as new bonds are formed. In an exothermic reaction, more energy is released when the bonds are formed in the products than is required to break the bonds in the reactants.

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  • Energy is used to break the bonds of the reactants.
  • Energy is released when the bonds of the products are formed.
  • Since more energy is released when the bonds are formed in the products than is used to break the bonds in the reactants, the reaction is exothermic and the temperature goes up.