1. Writing and Balancing Chemical Equations
(Sec 9.2 pg )

2. According to the law of conservation of mass the amount of each atom you start with is the same as the amount of each atom you end with.
A skeleton equation is a chemical equation that has not yet been balanced. It does not satisfy the law of conservation of mass…yet.

3. In order to balance a chemical equation we need to count the number of each type of atoms.

4. The number in front of a compound (called a coefficient)represents how many molecules are present of that compound.
5 CO = five molecules of carbon monoxide.

5. CH2 = 1 carbon and 2 hydrogen.
As you know, any subscript number only applies to the compound in front of it.
CH2 = 1 carbon and 2 hydrogen.

6. Anything in brackets is treated as a group.
2(CO3) = 2 carbon and 6 oxygen
(CO3)2 = 2 carbon and 6 oxygen

7. There are lots of strategies you can use to balance equations.
Your textbook outlines one strategy.
Let’s take a look at how that strategy works

8. Element
Before
After C 6 1 H 12 2 O 8 3
C6H12O6 + 6O CO2 + 6H2O