Balancing Equations…30

Balancing Equations Notes…29 Equations must be balanced because matter can’t be created or destroyed- Law of Conservation of Mass Must have equal numbers of atoms of each element on both sides When balancing equations you may only add a coefficient. You may NOT change a subscript! (this will change the compound)

3H20 Subscript Coefficient

NaNO3 2NaNO3 Na: Na: N: N: O: O:

MgPO3 6MgPO3 Mg: Mg: P: P: O: O:

Ex. 1: Na + I2 NaI + Na I Na I I I Na Na

Ex. 2: K2O + H2O KOH K K K H H O H + O K O H O

Ex. 3: Mg + HCl MgCl2 + H2 H Cl Mg + H Cl Mg + H H Cl Cl

Ex. 4: S + O2 SO3 O + O S S O O O

Ex. 5: CH4 + O2 CO2 + H2O Hint: Fix the hydrogen's first! Balancing Equations