Chemical Reactions Intro

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Chemical Reactions introduction:

Chemical Reactions introduction Mrs. Trejo Chemistry class

Key terms-Google definitions:

Key terms-Google definitions Reactants : a substance that takes part in and undergoes change during a reaction Products : A product is a substance that is formed as the result of a chemical reaction. 

Google Definition: :

Google Definition: a process that involves rearrangement of the molecular or ionic structure of a substance, as opposed to a change in physical form or a nuclear reaction . Can you define chemical reactions in your own words? Do you know of any examples of chemical reactions?

Examples: :


There are Six types of chemical reactions!:

There are Six types of chemical reactions! Can you think of one?

1. Synthesis :

1. Synthesis Reaction in which two o r more elements combine chemically to give a compound General Equation A + B → A B Examples 2H 2 + O 2 → 2H 2 O What two elements undergo a synthesis reaction to form the molecule that forms salt?

2. Decomposition:

2. Decomposition Reaction in which a compound is broken down into simpler elements General Equation A B → A + B Example 2H 2 O → 2H 2 + O 2 Breakup Example + →

3. Substitution/Single Replacement:

3. Substitution/Single Replacement Reaction in which an atom or group of atoms is replaced by another atom or group In the last two explanations we have been using the world elements . Are atoms and elements synonyms? Explain. All matter are made up of atoms (or other things, like molecules, that are made from atoms!) Elements are the kinds of atoms that we have. (e.g. Hydrogen, Carbon, Oxygen). General Equation A + B C → A C + B OR A + B C → B A + C Example Zn + 2HCl → ZnCl 2 +H 2 OR Cl 2 + 2NaBr → 2NaCl + Br 2

3. Substitution/Single Replacement Example:

3. Substitution/Single Replacement Example + + → Think about substitution/single replacement chemical reaction a s a Fred cheating on Wilma with Betty (Flintstones).

4. Precipitation/ Double Replacement:

4. Precipitation/ Double Replacement Reaction in which a solid compound is formed when solutions of two soluble compounds are mixed. General Equation A B + C D → A D + C B Example AgNO 3 + NaCl → AgCl + NaNO 3 + → + Think of the precipitation/Double replacement c hemical reaction as Wilma and Betty changing h usbands for the day (Flintstones).

5. Naturalization or Acid/base:

5. Naturalization or Acid/base Reaction in which a solid compound is formed when solutions of two soluble compounds are mixed General Equation H A + B OH → H 2 O + B A Example HCl + NaOH → H 2 O + NaCl

5. Naturalization or Acid/base Examples:

5. Naturalization or Acid/base Examples

6. Redox or reduction/oxidation:

6. Redox or reduction/oxidation Reaction in which electron transfer occurs General Equation Reduction: A → A + e- Oxidation: B + e- → B- Example 2Na+ Cl 2 → 2NaCl Cl 2 + 2e- → 2Cl (gains electrons) Na → Na+ + e- (loss of electrons) From the equations above, which one represents reduction and which one represent oxidation ?

6. Redox or reduction/oxidation Examples:

6. Redox or reduction/oxidation Examples Explain how a battery works based on the concept of redox reactions and by examining the picture to the right. What are some acronyms to help you remember Redox reactions? OIL and RIG LEO goes GER

So What is the Point?:

So What is the Point? Conclusion Energy is neither created or destroyed A chemical reaction is a system that affects the energy change Happens all the time, happening currently in your body and in the world arounds us! Energy vs Reaction Graph

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