How Do You Do Molar Conversions?

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Because molar mass is calculated using a grams per mole unit, it can be used as a conversion factor to determine either the total number of moles or the total number of grams of compound. The conversion requires only a simple calculator to convert grams to moles or to convert moles to grams.

  1. Find the molar mass

    Find the molar mass either from a reference table or from calculating based on the atomic mass of each atom in the compound. To calculate the molar mass, divide the total atomic weight of each atom of an element by 1 mole of a substance. Add these numbers together to find the total molar mass.

  2. Choose the correct formula

    When converting from moles to grams, the correct formula is the product of the total number of moles times the molar mass in grams per mole. The mole units cancel out, leaving the total grams. For the reverse, convert from grams to moles by multiplying the total number of grams by the inverse of the molar mass, writing it as moles per gram.

  3. Plug the numbers into the equation

    To complete the conversion, plug the numbers into the appropriate part of the equation. Double-check that the units cancel out properly.