That's actually pretty close. "V" is volume, usually measured in liters, and "M" is molarity, measuring in mol/L, so "VM" is just moles. "N" is usually the normal force, which is "mg" on a flat surface and buoyancy is the weight of the displaced fluid and weight is also measured as "mg". So doing a dimensional analysis of "NVM" leaves us with kg x m/s^2 x L x mol x L with then give us . . .