mass
'no magic to the mole'
amount
molar mass
concentration
solution volume
gas volume
molar gas volume
Avogadro
constant, L
number of
entities, N
Now try the following question.
This is not the only way to express the concentration of a solution and others may assume importance depending on the situation: mass concentration, parts per million (ppm), % (w/w) are just three examples.
Formerly, the litre was not strictly the same as a volume expressed in cubic decimetres but, working to 4 s.f.,
it made no diference. Following a re-definition, their equivalence is now recognized within SI; use of the litre
is widespread in the USA and, for example, in medicine and pharmacology. And so mole per litre or mol / L are perfectly acceptable; these may even be preferable if there are issues dealing with indices.
Upper case L as the unit symbol for litre is permitted by S.I. due to possible misinterpretation of the lower case 'l' in some typefaces, particularly sans-serif fonts, and when handwriting.