CHEMICAL REACTIONS!By: LoudElectronicFerocious

YOU REALLY SHOULD KNOW THIS

Reactants• The substance that is reacting.

Products• The substance that is formed.

Valence Electrons• Reactions are all due to the number of valence

electrons.• Noble gases do not react because they already

have eight valence electrons. Visionlearning.com/library/module_viewer.php?mid=54

TYPES OF CHEMICAL

REACTIONS

In a chemical reaction, matter is not destroyed nor created in any regular reaction, so says the law of conservation of mass. More simply put, the mass of the product is always equal to the mass of the reactants.http://www.mi.mun.ca/users/edurnfor/1100/atomic%20structure/tsld004.htm

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TYPES OF CHEMICAL REACTIONSSynthesis Reaction-

• Two or more substances combine to make a more complex substance.

• Example- Simple hydrogen and simple oxygen make water.

Decomposition Reaction-• Complex substances break into simpler parts. Decomposition is the opposite of synthesis.

• Example- Water breaking down into hydrogen and oxygen.

TYPES OF CHEMICAL REACTIONS(CONTINUED) Single Replacement Reaction-

• A single, uncombined element replaces another element in a compound.

• Example- When zinc combines with hydrochloric acid and replaces hydrogen.

Double Replacement Reaction-• Parts of two compounds switch places to

form new compounds.• Example- Silver nitrate combines with

sodium chloride makes two new compounds because sodium switched with silver.

Usoe.k12.ut.us/CURR/Science/sciber00/8th/matter/sciber/chemtype.htm

TYPES OF CHEMICAL REACTIONS (CONTINUED)

Combustion Reaction-• When all substances

are combined with oxygen. Combustion produces carbon dioxide and water. It is also commonly known as burning.

• Example- Methanol burning shows a combustion reaction.

CxHy + O2 --> CO2 + H2O

Library.thinkquest.org/2923/react.html

www.chem.uiuc.edu/clcwebsite/meth.html

CHEMICAL FORMULAS

Synthesis• To tell if a reaction is synthesis, the formula has to

have two or more reactants, and only one product.

Decomposition• To tell if a reaction is decomposition, there must

be one reactant that decays into two products.

Single Replacement• To tell if a reaction is single replacement, there

must be two reactants and two products, and one of the reactants must have taken the place of another in a bond.

CHEMICAL FORMULAS (CONTINUED)

Double Replacement• To tell if a reaction is double replacement, there

must be two reactants and two products, and two of the reactants must switch places to turn into the product.

Combustion• To tell if a reaction is combustion, the reactant

must be combined with oxygen to make the product.

SIGNS OF CHEMICAL REACTIONS

http://www.sciencecodex.com/graphics/microfluid%20bubbles.jpg

SIGNS OF CHEMICAL REACTIONS

Color Change When a piece of

metal rusts, the color changes from silver to a reddish-brown.

Change in Temperature• When a chemical

produces or loses any heat or energy.

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http://www.jamstec.go.jp/frsgc/jp/publications/news/no25/eng/images/p03_2.jpg

SIGNS OF A CHEMICAL REACTION (CONTINUED)

Change in Form• When matter changes

shape or appearance. For example, burning paper.

Formation of a Precipitate• When a solid is formed

that differs from the reactant. Usually they are ionic compounds to form insoluble product.

http://www.cgsco.com/images/colin.jpg

http://farm1.static.flickr.com/62/198469373_14457c497b.jpg

SIGNS OF A CHEMICAL REACTION (CONTINUED)

Decomposition of Organic Matter• When an organic

material breaks down. Two examples could be rotting logs or food.

Formation of a Gas• When a gas is created,

usually as bubbles.

Ansers.yahoo.com/question/index?qid=20081109193239AAsxvbW

http://i.pbase.com/u37/gwilburn/upload/24122849.20031213079mrottinglograttraymarsh.jpg

http://www.scienceclarified.com/images/uesc_09_img0486.jpg

EXOTHERMIC REACTIONS Exothermic Reactions

• When newly bonded atoms have a lower chemical energy than the atom before being bonded. This means more energy exists to produce a light or heat.

• Most reactions are exothermic.

http://chemsite.lsrhs.net/chemkinetics/reactionsAndPotential.html

• Examples: A thermite reaction using Iron(III) Oxide (right)

Adding water to anhydrous copper(II) sulfate.

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

ENDOTHERMIC REACTIONEndothermic Reaction

•When reactants have less energy than the products, so more energy, usually heat, is needed .•Usually described as a “cold reaction”

Nationmaster.com/encyclopedia/Endothermic-reaction

•Example: mixing sodium and chlorine to make table salt.

http://chemistry.about.com/cs/generalchemistry/a/aa051903a.htm

jchemed.chem.wisc.edu/.../MAIN/ENDO2/PAGE1.HTM

THE ROLE OF ENERGY All reactions also need two reactants, which start the

reaction.http://answers.yahoo.com/question/index?qid=20080621044544AAYELRh

Potential energy is stored energy. Chemical potential energy is stored in the bonds of atoms and atoms that keeps these particles held together.

http://www.eia.doe.gov/kids/energyfacts/science/formsofenergy.html

Every chemical reaction comes with an energy that must be overcome so the reaction can actually take place. This is the activation energy, or midnight energy. It was introduced in 1889 by a Swedish man named Svante Arrhenius. Simply, it is the minimal energy need for the reaction to take place.

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

Bibliography “Chemical Reactions”

Visionlearning.com/library/module_viewer.php?mid=54 “The Law of Conservation of Mass”

http://www.mi.mun.ca/users/edurnfor/1100/atomic%20structure/tsld004.htm “Types of Reactions”

Usoe.k12.ut.us/CURR/Science/sciber00/8th/matter/sciber/chemtype.htm “Combustion”

Library.thinkquest.org/2923/react.html “What are the Signs of a Chemical Reaction?”

http://wiki.answers.com/Q/What_affects_the_rate_of_a_chemical_reaction “Chemical Reactions and Potential Energy”

http://chemsite.lsrhs.net/chemkinetics/reactionsAndPotential.html “Examples of Exothermic Reactions”

http://en.wikipedia.org/wiki/Exothermic_reaction#Examples_of_exothermic_reactions “Exothermic and Endothermic Reactions”

http://chemistry.about.com/cs/generalchemistry/a/aa051903a.htm “What is the Role of Energy In a Reaction?”

http://answers.yahoo.com/question/index?qid=20080621044544AAYELRh “Potential Energy”

http://www.eia.doe.gov/kids/energyfacts/science/formsofenergy.html “Activation Energy”

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

THE END!

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