Final answer:
The molecular mass refers to the mass of one molecule, often in atomic mass units, while molar mass is the mass of one mole of that substance in grams per mole. They have the same numerical value, but different units of measurement.
Step-by-step explanation:
The correct answer to the question is 'c' Molar mass is the mass of one mole, molecular mass is the mass of one molecule. Molecular mass is a measure of the mass of a single molecule and is typically expressed in atomic mass units (amu). On the other hand, molar mass refers to the mass of one mole (6.022 × 1023 entities) of a substance and is expressed in grams per mole (g/mol).
Although the molecular mass and molar mass of a compound share the same numerical value, their units differ. For example, the molecular mass of a molecule might be 58.080 amu, while its molar mass would be 58.080 g/mol. The relationship of molar mass to molecular mass is critical in calculations involving the conversion between moles and grams of a substance.