how to calculate %w/w of a liquid
Percent solutions can take the form of weight/volume % (wt/vol % or w/v %), weight/weight % (wt/wt % or w/w %), or volume/volume % (vol/vol % or v/v %). In each case, the percentage concentration is calculated as the fraction of the weight or volume of the solute related to the total weight or volume of the solution.Because percent solutions can be expressed in three different ways, it is imperative that the type of percent solution be explicitly stated.If this information is not provided, the end user is left to guess whether w/v %, w/w %, or v/v % was used.or example, a 70 % (v/v) solution of ethanol can be prepared by dissolving 70 mL of 100% (i.e., 200 proof) ethanol in a total solution volume of 100 mL. Other factors may also be important when deciding on the type of percent solution to prepare.