Chemical Reactions

By: Stephayy81

Chemical Reaction Basics

Reactant: The substance that is participating in the reaction.

Product: A substance that is formed as a result of the chemical reaction.

What's Happening?Every type of chemical reaction differs, however, in simplest terms, bonds are broken and formed by the

interactions of electrons.

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

http://www.chem4kids.com/files/react_intro.html

Signs of a Chemical Reaction

A formation of a gas is one way to tell that a chemical

reaction has taken place.

A formation of a solid is another way to tell that a chemical reaction has taken place.

http://wiki.answers.com/Q/What_are_the_5_signs_of_a_chemical_reaction

http://www.dkimages.com/discover/previews/857/35080206.jpg

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

Signs of a Chemical Reaction

If a chemical has changed color or has produced energy, it’s a sign that a chemical reaction has taken place.

http://wiki.answers.com/Q/What_are_the_5_signs_of_a_chemical_reaction

http://farm1.static.flickr.com/169/473829711_dbc72f45b9.jpg?v=0

http://static.howstuffworks.com/gif/light-stick-2.jpg

Signs of a Chemical Reaction

One last way to tell if a chemical

reaction has taken place is a change in temperature.

http://www.northernbrewer.com/pics/fullsize/lab-thermometer.jpg

http://wiki.answers.com/Q/What_are_the_5_signs_of_a_chemical_reaction

Law of Conservation of Mass

The law of conservation of mass, states that in a chemical reaction,

mass cannot be destroyed nor created. So the mass of a products

always equal to the mass of the reactants.

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

Energy and Chemical Reactions

Chemical potential energy is the energy stored in the bonds of atoms

or molecules.

For example, when fuel is burning, the energy is transformed into heat.

http://en.wikipedia.org/wiki/Potential_energy#Chemical_potential_energy

Activation Energy

Activation energy is energy that must be overcome in order for a chemical reaction to occur.

For a reaction to occur between two colliding molecules, the molecules must collide in the correct arrangement and must possess a minimum amount of energy.

http://www.bio-medicine.org/biology-definition/Activation_energy/

Exothermic Reactions

An exothermic reaction is a chemical reaction that releases heat.

For example, the burning of wood is an example of an exothermic reaction.

http://www2.mst.dk/Udgiv/publications/2007/978-87-7052-501-5/html/images/s19.jpghttp://en.wikipedia.org/wiki/Exothermic_reaction

Endothermic Reactions

An endothermic reaction absorbs as much energy as possible.

An example of an endothermic reaction is melting ice.

http://en.wikipedia.org/wiki/Endothermic_reaction#Implications_for_chemical_reactions http://dillpickletheater.com/REMSL/images/ice_melt2.jpg

Types of Chemical Reactions

In a synthesis reaction, two or more simple substance combine to form a more complex substance.

Example:Hydrogen gas combined with Oxygen gas produces water.2 H2 + O2 2 H2O

How to tell:If two or more reactants yield one substance.

http://misterguch.brinkster.net/6typesofchemicalrxn.htmlhttp://z.about.com/d/longevity/1/0/Q/0/-/-/water.jpg

Decomposition Reaction

In a decomposition reaction, a more complex substance breaks down into its more simple parts.

How to tell:One reactant yields two or more products.

Example:Water can be broken down into hydrogen gas and oxygen gas.2 H20 2 H2 + O

http://misterguch.brinkster.net/6typesofchemicalrxn.html https://www.llnl.gov/str/October05/gifs/Mundy2.jpg

Combustion Reaction

A combustion reaction is when Oxygen is a reactant.

How to tell:It is an exothermic reaction, and produces heat.

Example:CH4 + 2O2 CO2 + 2H20

http://blog.wired.com/photos/uncategorized/2007/10/09/oxygen_logo.jpg

http://misterguch.brinkster.net/6typesofchemicalrxn.html

Single Replacement

In a single replacement, one element trades places with another element in a compound.

How to tell:You’ll see two reactants yield two products.

Example:Mg + 2 HCI MgCI2 + H2

http://misterguch.brinkster.net/6typesofchemicalrxn.html http://www.zephyrus.co.uk/magnesium.gif

Double Replacement

In a double replacement reaction, anions and cations of two different molecules switch places, producing two different compounds.

How to tell:You’ll see two reactants yield two products.

Example:Pb(NO3)2 + 2 KI ---> PbI2 + 2 KNO3

http://acswebapplications.acs.org/portaltools/shopper/images/pb.jpghttp://misterguch.brinkster.net/6typesofchemicalrxn.html

http://www.atariarchives.org/mmm/thats_all.gif