Chemical Reactions!

Process Page

Student Page:

Introduction
Task
 

Process:

Solutions
Acids, Bases, Salts
Chemical Rxn
Chemical Bonds
 

Conclusion:

Evaluation
Credits
 

Teacher Page:

Introduction
PA State Standards
Task

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• Mixtures are a combination of substances not in a specific ratio.  There are two types of mixtures; heterogeneous and homogeneous.  Solutions are a type of homogeneous mixture where the solute is dissolved into a solvent.  An example would be salt dissolved into water to give you a salt water mixture.  Not all salt water "taste" as salty but it is all salt water.  Why?  Solubility of a substance is the amount of solute that can be dissolved in a certain amount of solvent.  A substance that is insoluble will not dissolve in the solvent.  Solutions can be described as either concentrated or diluted.  When the solution has dissolved all of the solute that it can dissolve the solution is described as saturated.  If more solute can be dissolved it is described as unsaturated.  When a solution has more solute then it can normally hold at a certain temperature it is described as supersaturated.
• Links:
• General Chemistry on-line
• Wikipedia
• Fact Monster

• Solutions

•  Many substances can be classified as an acid, base, or salt.  Acids, Bases, and Salts all have different properties to help tell them apart.  Taste is one way but do not go around tasting chemicals because many are poisonous!!  Salts are forms when an acid and a base are mixed together.  This process is called neutralization.  Explain how this works?  Alkalinity is measured using the pH scale.   Indicators are chemical compounds which change color in the presents of acids, bases, and salts.  Indicators include pH meters and papers, phenol red, phenophthalein, and litmus paper.  Acids, Bases and Salts are usually made from both metal and nonmetal ions (ionic compounds).  

• Links:
• Fact Monster
• Acid and Base Indicators
• Household Indicators
• All About Chemistry

• When substances are mixed together, elements within the substances may react together.  This is what causes a chemical change or reaction to occur.  There are four signs of a chemical reactions.  At least one of these indicators must be present in order for a chemical change occur.   In addition, all chemical reactions involve energy transfer.  Exothermic or Endothermic energy is observed in all reactions.  Chemical reactions are represented by chemical equations.  All equations have reactants to start the reaction and products which are created by the reaction.  Both the reactant side and the product side of an equation must show equal or balanced amounts of substances.  This is supported by  the Law of Conservation of Mass and writing balanced chemical equations.   There are four types of  chemical reactions; synthesis, decomposition, single and double replacement (displacement).  Reactions are influenced by four different factors; temperature, concentration, surface area (particle size) or additives (catalyst or inhibitor).
• Links:
• Types of Chemical Reactions
• Chemical Equations
• Chemical Changes
• Exothermic and Endothermic examples
• How to balance equations

• When substances form compounds during reactions, electrons in the outer energy shell are either transferred or shared between elements.  There are three main types of bonds which form during reactions:  ionic, covalent, and metallic bonds.   Electrons during bonding can be represented by using the Electron Dot Diagrams.

• Links:
• Chemical Bonding
• Stability of Atoms
• Electron Configurations
• Elements