Chemistry · Reactions and the law of conservation of mass

Balancing Chemical Equations Explorer

Pick an unbalanced equation and change the coefficients with the sliders. The atom counts on each side update at once, and a balance beam shows what happens to the total mass of each side.

A balanced equation has the same number of atoms of every element on both sides, and the coefficients in the lowest whole-number ratio. Subscripts inside formulas never change, only the coefficients do.

Model notes

Atomic masses (g/mol): H 1.008, C 12.011, N 14.007, O 15.999, Al 26.982, P 30.974, Cl 35.45, K 39.098, Ca 40.078, Fe 55.845.
The beam compares the total molar mass on each side, which is the mass of one mole of each formula unit multiplied by its coefficient. The two sides match only when the equation is balanced.
The equations are standard textbook reactions. Some, such as the burning of glucose, are summaries of many steps.
This page shows the counting rule only. It does not decide whether a reaction actually occurs.

Sources

OpenStax Chemistry 2e, Section 4.1: Writing and Balancing Chemical Equations

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