Graham’s Law Calculator

This Graham's law calculator works out how much faster one gas effuses or diffuses compared with another, based purely on their molar masses. Graham's law states that the rate of effusion or diffusion of a gas is inversely proportional to the square root of its molar mass, so lighter gas molecules move through a small opening or spread through another gas noticeably faster than heavier ones. You enter the molar mass of gas 1 and the molar mass of gas 2, both in grams per mole, and the calculator returns the rate ratio as rate 1 divided by rate 2, along with the inverse ratio of rate 2 divided by rate 1, and a plain-English note on which gas is faster. Underneath the result you will find the formula itself, rate 1 over rate 2 equals the square root of M2 over M1, plus a worked example comparing helium at 4 g/mol with oxygen at 32 g/mol, showing helium effusing about 2.83 times faster. It suits chemistry students, teachers and lab workers, and explains everyday effects such as why a helium balloon deflates faster than one filled with air, plus industrial processes like gas separation and uranium enrichment. The calculation assumes both gases are at the same temperature and pressure, and results are rounded, so treat the output as a teaching estimate rather than a precision laboratory figure.

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