Chemical equations are a specific description of what happens in a reaction Ex. 2H 2 O  2H 2 + O 2

2 parts - Chem. equations 1. Reactants (left of arrow) 2. Products (right of arrow) - substances that undergo a reaction - new substances produced

Balancing Chem. Equations è law of conservation of mass must be followed Mass/matter (atoms) cannot be created or destroyed in a reaction

Use coefficients - balance # of atoms on each side of arrow CO 2 + LiOH  Li 2 CO 3 + H 2 O Example C -1 O - 3 Li - 1 H - 1 C -1 O - 4 Li - 2 H - 2

Do not change the subscripts When trying to balance both sides of the equation

CO 2 + LiOH  Li 2 CO 3 + H 2 O Carbon - 1 Lithium - 2 Oxygen - 4 Hydrogen is the coefficent

Cl 2 + NaBr  NaCl + Br 2 2 2