Molar concentration

Molar concentration is a measure of the concentration of a solution. It is defined as moles of solute per litre of solution, and has units of mol dm-3.

$$C=\frac{N/A}{V}$$

Here, N is the number of molecules present in the volume. This latter is measured in litres. A is the Avogadro's number, 6.022×1023

Molar concentration is also often represented by a capital m (M)

Another formula that may be used is M=n/v, where M is the molar concentration, n is the number of moles and v is the volume in litres.

Examples
Most proteins are present in the bacteria E.Coli at 60 copies or fewer. The volume of the bacteria is 10-15 litre, which gives us C=10-7 M =100nM. (nM is nanomolar i.e. 10-9).

2 grams of NaCl dissolved in 5mL of Water. As 58 grams of NaCl is 1 mol of molecules, and 1mL is 0.001 litre\\?, this gives C=(2/58)/0.005=6.9 M.