Final answer:
The molar mass of a monatomic element is the atomic mass from the periodic table, while the molecular molar mass is the sum of molar masses of all the atoms. To convert between them, you may need to break down a molecule into its atoms and use the individual atomic masses as molar masses.
Step-by-step explanation:
To calculate the molar mass of a monatomic element, you can simply look up the atomic mass of that element on the periodic table and use that value directly as the molar mass, expressed in grams per mole. On the other hand, the molecular molar mass is the sum of the molar masses of all the atoms in a molecule. For instance, for water (H2O), the molecular molar mass is calculated by adding together the molar masses of two hydrogen atoms and one oxygen atom (2x1.008 g/mol for hydrogen + 15.999 g/mol for oxygen = 18.015 g/mol for water).
When converting from molecular molar mass to monatomic molar mass, you are generally breaking down a molecule into its constituent atoms and using the atomic masses of those individual elements as their molar masses. This process is fundamentally conceptual unless you are dealing with a breakdown of a compound into its elements through chemical reactions.
For example, if you need to find the molar mass of the atoms in a molecule of CO2, you would consider the atomic molar masses of carbon (12.01 g/mol) and oxygen (15.999 g/mol), but you would simply take the values for the individual elements without adding them together, as you would do for the molecular molar mass.
Remember, to convert moles to grams, or vice versa, of a substance, you need to multiply or divide, respectively, by the molar mass of the substance under consideration.