Chemical Equations and Reactions

​Chemical Equations and Reactions

​Law of Conservation of Mass

​Matter cannot be created or destroyed. Therefore, you must have the same number of atoms on both sides of a chemical reaction.

​Evidence of a Chemical Reaction

1. ​Change in temperature

2. ​Evolution of gas

3. ​Formation of a percipitate

4. Color Change

5. Odor Change​

​Classifications of Reactions

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• Combination reaction.

• Combustion reaction.

• Neutralization reaction.

• Single displacement reaction.

• Double displacement reaction.

• Precipitation reaction.

• Redox reaction.

• ​Decomposition reaction.

Poll

Is it possible for a chemical reaction to fall under more than one classification?

• Yes

• No

Open Ended

What other examples of a chemical reaction can you think of in your everyday life?

Multiple Choice

How many atoms of each type do you have in the following equation? $$Mg\left(OH\ \right)_2+\ 2HCl\ \rightarrow\ 2H_2O\ +\ MgCl_2$$  

• 1 Mg, 2 OH, 2 H, 2 Cl

• 1 Mg, 4 H, 2 O, 2 Cl

• 2 HCl, 2 OH, 1 Mg, 2 Cl

• 2HCl, 2 OH, 1 Mg, 2 $$H_2O$$  , 2 Cl

​Combination Reaction

​A combination reaction takes to seperate chemicals and combines them to form one new chemical.

​

​This reaction is also known as a synthesis reaction.

​Decompostion Reaction

​Takes one chemical and seperates it (breaks it apart) into two or more different (new) chemicals.

Multiple Choice

The reaction of Magnesium and Oxygen, that you observed in class, is what type of chemical reaction?

$$2Mg\ +\ O_2\rightarrow\ 2MgO$$  

• Combustion

• Synthesis

• Decompostion

• Single Replacement

​Single Displacement Reaction

​Double Replacement Reaction