Chemistry
Balancing Chemical Equations
A chemical equation is balanced when the number of atoms of each element is the same on both sides. Most equations can be balanced by inspection — adjusting coefficients until the atom counts match.
How to Approach Balancing Chemical Equations
Count atoms on each side
List each element. Count how many appear on the left (reactants) and the right (products).
Balance one element at a time
Start with the element that appears in only one molecule on each side. Adjust coefficients in front of molecules — never change subscripts.
Check & adjust
After balancing one element, recount the others. Iterate until every element balances. Finally, reduce coefficients to lowest whole numbers.
Frequently Asked Questions
Why can't I change subscripts to balance?+
Subscripts define the chemical identity. H₂O is water; HO is not. Coefficients tell you how many molecules — those are what you adjust.
What about redox equations?+
Use the half-reaction method: split into oxidation and reduction, balance atoms and charges separately, then combine. ScanSolve handles redox balancing with electron tracking.
Can chemical equations have fractional coefficients?+
In intermediate steps, yes. Multiply through by the smallest integer that clears fractions to get the final balanced form with whole-number coefficients.
Related Topics
More step-by-step guides in Chemistry and adjacent subjects.
Stuck on a Balancing Chemical Equations problem?
Snap a photo or type the question. ScanSolve walks you through every step — same as the worked examples above. 5 free solves per day, no card required.