http://www.chemistryexplained.com/images/chfa_01_img0184.jpg

Chemical Reaction- When substances change chemically to form a new substance.

1. Forms new bonds between atoms.

2. Make new substances

3. Example-

2 hydrogen atoms (gas) +1 oxygen atom (gas) react to form 1 water molecule (h20)

What happens in a reaction?

1. Reactants react to create a product.

Reactants- the materials that exist before the chemical reaction

Products- Substances that are created by the chemical reaction

2. In a reaction atoms are arranged and no new atoms are created.

Electrons are the atoms that are effected by the chemical reaction.

Law of Conservation of mass is a relation saying that during the reaction the mass is neither created or destroyed.

4. The temperature of the chemical changes from before.

2. The chemical changes color.

1. A gas is produced

3. Chemical starts to bubble.

How do you know a reaction occurred?

All pictures from http://www.harpercollege.edu/tm-ps/chm/100/dgodambe/thedisk/chemrxn/signs4.htm

Energy is needed to break chemical bonds so they can start a chemical reaction. Energy is released when bonds form.

Chemical Energy- energy that is stored in atoms and molecules. Chemical energy can be released during a reaction.

Endothermic- Photosynthesis is an example of an endothermic reaction. Plants use the energy to form the sun to convert carbon dioxide and water into the glucose and oxygen.

Exothermic- Mixture of sodium and chlorine to yield table salt. This reaction produces 411 (kj) of energy for each mole of salt that is produced.

Potential Energy is stored energy of position of an object.

Activation Energy is usually when the chemical reaction result as a collusion between reacting particles.

Image1:http://www.glenbrook.k12.il.us/gbssci/phys/Class/energy/u5l1b.htmlImage2:http://www.chemgapedia.de/vsengine/media/vsc/en/ch/12/oc/substitution/sn_2/aktivierungsenergie_sn2/tempkurven.gif

Exothermic processes

Making ice cubesFormation of snow in cloudsCondensation of rain from water vaporA candle flame

Mixing sodium sulfite and bleachRusting ironBurning sugarForming ion pairsCombining atoms to make a gas phaseMixing water and strong acidsMixing water with an anhydrous saltCrystallizing liquid salts Nuclear fission

Mixing water with calcium chloride

Endothermic processes

Melting ice cubesConversion of frost to water vapor Evaporation of waterForming a cation from an atom in the gas phase Baking breadCooking an eggProducing sugar by photosynthesisSeparating ion pairsSplitting a gas molecule apartMixing water and ammonium nitrate Making an anrous salt from a hydrateMelting solid saltsReaction of barium hydroxide crystals with dry ammonium chlorideReaction of thionyl chloride (SOCl2) with cobalt(II) sulfate heptahydrate

Exothermic Reactions- Reactions that releases energy and the temperature gets hotter.Endothermic Reactions- Reactions that absorbs energy and the temperature gets colder.This graph is showing the differences between exothermic & endothermic processes. These experiments above can be tested. An exothermic reaction watch how the temperature of the process increases and during endothermic watch how the temperature drops.

http://en.wikipedia.org/wiki/Exothermic_reaction

http://www.citycollegiate.com/chapter2a.htm

Synthesis Reaction- a combo of two substances and a compound result.

Decomposition Reaction- when a compound is broken down into a easier substance.

Single Replacement-A metal replaces a metal or a non-metal replaces a non-metal.

Double Replacement- a metal always replaces a metal & a non-metal always replaces a non-metal.

Combustion Reaction- always includes oxygen. Anytime it burns it is a combustion reaction.

http://www2.hn.psu.edu/faculty/dmencer/combustion/combust_app.gif