Balancing Equations!!

sorry for the late post :S
but YAY for a change we got something easy to do! Balancing Chemical Equations :)
this is review from grade 9 and 10! if you forgot... heres how it goes.

What is a Chemical Equation?

When a chemical reation occurs it can be described as a equation. It shows the chemical that react, called the reactants which are located on the left hand side. Also the chemicals that they produce, called products which are located on the right hand side of the equation. These two sides are seperated by an arrow that indicated the reactants form the product.

The Concept:

Take a look at this chemical word equation:

Ethane + Oxygen  Carbon Dioxide + Steam

This is the writen equation, now you have to translate it to the chemical equation:

C₂H₆ + O₂ CO₂ + H₂O

In this equation notice how neither the Carbon, Hydrogen or Oxygen atoms match from the left hand side to the right hand side? 

Left has: 2 Carbon, 6 Hydrogen, 2 Oxygen

Right has: 1 Carbon, 2 Hydrogen, 3 Oxygen  

This is why we must balance the equation!

Since there are two carbon atoms on the left side, but only one on the right, so we need to put a 2 in front of the carbon dioxide molecule to give two carbons on each side:

C₂H₆ + O₂  2CO₂ + H₂O

Now we will look at the hydrogen atoms. There are six hydrogen atoms on the left side and two on the right side, so now we have to put a 3 on the right hand side so it is equal to the number of hydrogen atoms on the left hand side:

C₂H₆ + O₂  2CO₂ + 3H₂O

Now there are two carbon atoms on each side, and six hydrogen atoms on each side, but the oxygen atoms don't match. There are 2 of them on the left side and 7 on the right side. This is easily solved by multiplying the oxygen molecule on the left side by 3.5 (as 2 x 3.5 = 7):

 

C₂H₆ + 3.5O₂  2CO₂ + 3H₂O

This gives 2 carbons, 6 hydrogens and 7 oxygens on each side of the equation. The equation is balanced, but rather than a decimal just double all the figures in the equation:

2C₂H₆ + 7O₂  4CO₂ + 6H₂O

YAY! now it is balanced :)

As you go on balancing those quations you may come across molecules as being a unit such as:

SO₄ Dont even worry about it, just go on about your business. Treat them the same way!

Also a note:

Watch out for Diatomic Elements which are specific elements that go around in pairs (atom of 2).

they include: Hydrogen(H2), Oxygen(O2), Flourine(F2), Bromine(Br2), Iodide(I2), Nitrogen(N2), and Clorine(Cl2)

So whenever you are writing a chemical equation, always remember, if u come across these elements alone, they come in pairs of 2!

To help you remember these elements just think: HOFBrINCl

 

HERE ARE SOME SEMI HELPFUL VIDEOS! 

http://www.youtube.com/watch?v=RnGu3xO2h74

http://www.youtube.com/watch?v=BVEvvqMGMSc