Why is the mole the center of the mole road map in regards to conversion factors?
It is the common link between all other conversions
Although mathematical relationships (conversions in terms) can take on any form or direction, the point of the "map" is to illustrate the fundamental position and importance of the MOLE in chemistry.
We measure in volumes and masses, but the chemistry takes place only as moles. Thus, the working conversions that we need to translate our physical observations into chemical information and knowledge all need to include the mole concept and conversions.
Everything in chemistry can be converted into moles.
A mole is a number of particles, Chemical reactions occur between particles.
Mass can be converted into moles by grams/ moles.
Volume can be converted into moles by Molar Volume at STP
The particles themselves can be converted to moles using avogardro's number.
The mole then becomes the universal currency that everything can be converted into.