Originally Posted by rosanna
4.2 pmol/l to pg/mL
14.1 pmol/l to ng/dL
1.19 uIU/mL to mIU/L
The first two involve converting moles to mass (grams). You have to know the molar mass of the substance. This is numerically equal to the molecular (or atomic) weight of the substance, computed from the chemical formula, and the atomic weight of each atom in the molecule. (They also involve adjusting prefixes). When you find the molar mass, in grams per mole, multiply by it then sort out prefixes as below.
The last one is only an exercise in prefix adjustment. You can do it in your head, but to show the work formally,
1.19 ÁIU/mL x 1 mIU/1000 ÁIU x 1000 mL/1L = 1.19 mIU/L
The two numeric factors of 1000 cancel each other and the unwanted units cancel out.