everyday examples exothermic reactions

Best Results From Wikipedia Yahoo Answers Youtube


From Wikipedia

Exothermic - Wikipedia, the free encyclopedia

1 Overview; 2 Examples; 3 Implications for chemical reactions; 4 See also; 5 External links; 6 References ... In an adiabatic system (e.g. a system that does not give off heat to the ... This light is equivalent in energy to the stabilization energy of the energy for the chemical reaction, i.e. the bond energy. ...


From Yahoo Answers

Question:What is the relationship between the temperature of an object and the motion of atoms? What is the difference between exothermic and endothermic reactions? What are three exmaples of exothermic reactions in everyday life? What is the difference between a physical and chemical change? Thanks.

Answers:1.) Higher the heat, higher agitation of particles (vibration, movement) 2.) Exothermic reactions release heat to the environment, endothermic reactions require heat (absorb heat) in order to react 3.) Any combustion reaction (fuels), Neutralization reactions (acid/base forming salt), most corrosive reactions (including rusting) 4.) Physical changes only change the state (solid/liquid/gas/plasma) Chemical changes alter the structure of the reacting molecule.

Question:Suppose you have to burn a piece of charcoal. During combustion of the charcoal heat energy is released, so it is exothermic reaction, but heat is required to start the whole burning process! When we ignite the fuel we need to light a march first, which first gives some heat energy to the charcoal before the charcoal starts reacting with oxygen in the air. But on thw whole, the heat energy released during burning is much more than that required to start the reaction, so it is exothermic? So at the beginning the burning of charcoal is an endothermic reaction, and after that it becomes exothermic? Can we separate combustion into 2 stages? Thanks!

Answers:This is a nice question. The overall reaction is exothermic, but as you point out the beginning part is endothermic. It turns out that the beginning part is vaporizing the coal into a gas so that it can burn. That process continues throughout time the coal is burning. Once there is enough vapor to ignite, the fire then supplies enough energy to vaporize more coal, as well as even more heat to do useful work. There is also something called activation energy. This is the energy required for a reaction to start. For example, in order to start the fire, there must be some spark to trigger it to burn, otherwise you would just have warm coal gas.

Question:Can you also tell me whether the reaction between acids and carbonates can be found in our everyday lives?

Answers:A good example can be when you experience heartburns or hyperacidity. When that happens, you drink something like, let's say, Rolaids. One of it's active ingredients is Calcium Carbonate (CaCO3). That reacts with the excess Hydrochloric Acid you're stomach produces to ease you of your heartburn/hyperacidity. It can be something like this: 2 HCl + CaCO3 = CO2 + H2O + CaCl2

Question:

Answers:The classical example of neutralization: HCl + NaOH -----> NaCl + H2O is really exothermic. The reason for a reaction to be exothermic is involved energy for breaking bonds and forming the new ones. You note that heat is released in this particular reaction because the energy absorbed during bond breaking (when H-Cl and Na-OH bondings break) is less than the energy released during Na+Cl- and H-OH bondings making).

From Youtube

Chemistry - Chemical Reactions :GET the PowerPoint at www.ZUMAed.com. This module begins with a brief review of atoms, ions, molecules, and elements. It continues with a discussion of what a chemical reaction is and the signs that one has occurred. The module concludes with a discussion of chemical equations and endothermic and exothermic reactions. 3 By the end of this presentation, students will be able to * Describe what happens during a chemical reaction. * Identify signs that a chemical reaction has occurred. * Give examples of common chemical reactions. * Write, balance, and interpret chemical equations representing simple chemical reactions. * Differentiate between endothermic and exothermic reactions.

Single Replacement Reaction (Exploding Egg) :This is not an exercise in teaching students to balance chemical equations (that skill is developed after students develop the following skills): 1. differentiating between elements, compound and mixtures 2. Learning to read the periodic table 3. Learning to tell the difference between chemical and physical properties 4. Integrating this knowledge so that students can understand why elements bond to form various compounds...or not 5. Learning about the different types of chemical reactions 6. Learning about the evidence of a chemical reaction 7. Learning about conservation of matter 8. And then finally applying this knowledge toward balancing chemical equations such that the mass of the reactants equals the mass of the products. Observation and inference are important skills for scientists to develop. Students at Parsons Junior High School in Redding, California participate in a hands-on science experience with direct application to California Science Standards. Students learn about safety procedures, the names of equipment, chemical reactions (in this example-a single replacement reaction), evidence of chemical reactions and their characteristics (ie, endothermic or exothermic, producing a gas, color change, or precipitate). This demonstration shows and egg exploding. It is really fun to do and the students enjoy it as well. If you have questions about the procedure, or reactions to the reaction (ha, ha), then drop me a note.