1. Describing Chemical Reactions
Chapter 6 Section 2
Describing Chemical Reactions

2. Chemical equations use chemical formulas and other symbols instead of words to summarize a reaction.
CONSERVATION OF MATTER; states that during a chemical reaction, matter is neither created nor destroyed. The total mass of the reactants must equal the total mass of the products.

3. Conservation of atom; In chemical reactions, the number of atoms stays the same no matter how they are arranged. So, their total mass stays the same.
To describe a reaction accurately, a chemical equation must show the same number of each type of atom on both sides of the equation
A coefficient is a number placed in front of a chemical formula in an equation.

4. Classifying Chemical Reactions
Synthesis
2Na + Cl2  2NaCl
Decomposition
H2CO3  H2O + CO2
Single Replacement
Zn + 2HCl  ZnCl2 + H2
Double Replacement
NaCl + AgNO3  NaNO3 + AgCl