convert mg/l to mmol/l

How do you convert 12.2 mg/l to mmol/l?

How do you convert 12.2 mg/l to mmol/l?

As previously discussed, you need to know the molecular weight of the fraction you are converting.

Consider:

mg/l is an expression of weight per volume, while mmol/l the amount of substance per liter (The official definition of the mole is "1 mole of particles is equal to the number of atoms in exactly 12g of carbon-12")

examples:
1 mole H2O is the number of molecules in 18.015 g H2O
1 mole H2 is the number of molecules in 2.016 g H2.

By knowing the molecular weight of a substance, you can convert its weight per liter to the amount per liter.

So, to answer your question, we need to know how many mg/l of what.