top of page

Chemical Equations

Overview: For students to learn the properties of a chemical equation. They will need to be able to understand the law of conservation of mass. The students will prove their understand of the law of conservation of mass through balancing equations. They will be able to identify the type of chemical reaction taking place from a balanced equation.

 

Enduring Understanding: A chemical equations shows how a chemical reaction (there are 5 types) occurs, which is indicated by the formulas, compounds, arrows (which mean "yields"), and other symbols such as the delta sign to indicate that heat has been applied to the reaction. Other than this, chemical equations must also be balanced (done by adjusting the coefficients of each compound/molecule). This is to make sure that a chemical reactant conforms to the law of conservation of mass (number of atoms must be equal on both sides). 

So How Do We Balance Equations? Heres an example:

  1. Write down the number of atoms of each element on both sides

    C3H8 + O2 â€”> H2O + CO2

    C = 3                  C = 1

    H = 8                 H = 2

    O = 2                 O = 2

  2.  Start with Carbon it's the first one from the left (easier): the left side has 3 carbon, and the right has 1, so we add 3 to the carbon on the right:

    C3H8 + O2 â€”> H2O + 3CO2

  3. Then balance the Hydrogen: the left side has 8 and the right has 2, so we add 4 in front of the hydrogen on the right:

    ​C3H8 + O2 â€”> 4H2O + 3CO2

  4. Then balance Oxygen: after balancing hydrogen and carbon, the left still has 2 oxygens, but the right has 10 oxygens. Therefore, we add 5 in front of the oxygen on the left side:

    C3H8 + 5O2 â€”> 4H20 + 3CO2

  5. Voilà!

    C3H8 + 5O2 â€”> 4H20 + 3CO2

5 Types of Chemical Reactions

  • SYNTHESIS/COMPOSITION

     

         A + X â€”> AX

 

  • DECOMPOSITION

     

         AX â€”> A + X

 

  • SINGLE DISPLACEMENT

     

         AX + B â€”> A + BX

 

  • DOUBLE DISPLACEMENT

     

         AX + BY â€”> AY + BX

 

  • COMBUSTION

     

         2H2 + O2 â€”> 2H2O

Strengths: My strength is demonstrating knowledge of all types of chemical reactions, as well as chemical equations. Because I have a deep understanding of what I've learned in this unit, there were only some minor difficulties during the test. 

Weaknesses: My weakness is making silly mistakes because I didn't read things properly.

bottom of page