6°C) (iii) Mass by volume percentage (w/V): Another unit which is
commonly used in medicine and pharmacy is mass by
volume percentage It is the mass of solute dissolved in
100 mL of the solution (iv) Parts per million: When a solute is present in trace quantities, it
is convenient to express concentration in parts per million (ppm)
and is defined as:
Parts per million =
 
6
Number of parts of the component
×10
Total number of parts of all components of the solution
(1