Balancing Chemical Equations
Balance the oxygen atoms:
Because you've added coefficients to the molecules on the right side of the equation, the number of oxygen atoms has changed.
Add a coefficient of 5 to the oxygen molecule on the left side of the equation. ...
C3H8 + 5O2 --> 4H2O + 3CO2.
The carbon, hydrogen, and oxygen atoms are balanced
How to balance a chemical equation with parentheses:
Remember with subscripts, any number to the right of parentheses multiplies each subscript within the parentheses. eg Fe2(SO4)3 contains 2 Fe atoms, 3 S atoms and 12 O atoms. 5. Finally make sure that all the coefficients are in the smallest possible whole number ratio.