Balance it · Chem Kit
Balance It Yourself (Grades 8–12)
You change the big numbers. The atom tally shows what matches. Chem Kit also adds up molar mass.
Written out
See the answer? Working it out is how it sticks.
Atom tally
| Element | Left | Picture | Right | Match? |
|---|
How each atom was counted
Roji's tip
Mass is conserved
Molar mass
Element by element
| Element | Atoms | Atomic mass | Subtotal | % of mass |
|---|---|---|---|---|
| Molar mass | ||||
Atoms × atomic mass = subtotal. Add the subtotals to get the molar mass in grams per mole (g/mol).
Roji asks
How this works
- Big numbers (coefficients) say how many of each molecule. You change these.
- Small numbers (subscripts) are part of the formula. They never change.
- An equation is balanced when each element has the same number of atoms on both sides, using the smallest whole numbers.
- Hints tell you where to look. They don't give you a number.
- Atomic masses are IUPAC standard values, rounded. Your periodic table may round a little differently.