This concentration unit is similar to ppm or ppb except it focuses on the solute as a percent (by mass) of the total solution. It is appropriate for realtively large solute concentrations. by definition we have
As an example consider 5 g sugar dissolved in 20 g of water. What is the w/w% concentration of sugar in this solution?
Now suppose we have 450 g of an NaCl solution that is 35 NaCl w/w %. What is the mass of NaCl ?