Balancing Equations

Law of Conservation of Matter Matter cannot be created or destroyed. Equations must be balanced Have equal numbers of each type of atom on each side.

Subscripts vs Coefficients Subscript multiplies the element or polyatomic ion it is attached to Small number to the right of symbol Coefficient multiplies the whole compound it is next to Big number in front of a compound

__Na + __H2O  __NaOH + __H2 Is it balanced? __Na + __H2O  __NaOH + __H2 Place coefficients in the blanks to balance. Mostly just trial and error. Never change subscripts, b/c it changes the substance. If polyatomic ions exist on both sides of the equation keep together as a group. Coefficients have to be at the smallest ratio. So reduce if necessary

___H2 + ___O2  ___H2O

___Fe2O3 + ___ H2  ___ Fe + ___ H2O

__Al +__HAsO3  __H2 +__Al(AsO3)3

___C6H14 + ___O2 → ___CO2 + ___H2O Sometimes you end up with and odd # on one side and an even # on the other– multiply all coefficients by 2 then balance