Final answer:
Dividing grams by gmol^-1 converts mass to moles using the molar mass of the substance as a conversion factor. This is a common conversion in chemistry that aids in stoichiometric calculations.
Step-by-step explanation:
When you divide grams by gmol-1, you are performing a conversion from mass to moles, which is a fundamental concept in chemistry.
The conversion factor used in this calculation is the substance's molar mass, which has units of grams per mole. Using the factor-label method, the unit grams in your quantity cancels out with the grams in the denominator of the molar mass, leaving your result in moles. This is an application of dimensional analysis, where units are treated algebraically to convert from one quantity to another.
This process is useful for determining the number of moles of a substance given its mass, which is important for chemical equations and stoichiometry.