408 



Solution Preparation (sec. 1) 



Percentage Solutions 



In the case of percentage solutions, it should be indicated in some way 

 as to whether the percentage is determined by weight or volume: either 

 written out in grams and milliliters or expressed thus: 



w/v means weight in grams in a 100 ml. volume of solution 



v/v means volume in milliliters in 100 ml. total volume of solution 



Although it is erroneous, a long-established habit of technicians is 

 maintained. Percentage solutions of liquids are diluted as though the 

 reagent solution is 100% concentration. That is, a 1% solution of acetic 

 acid is 1 ?nl. of glacial acetic acid in 99 ml. of distilled water. In most 

 procedures the dilution is indicated in parentheses following the per- 

 centage desired. 



Dilutions for IN Solutions.* 



* Calculated from Norbert Adolph Lange, 1956, Handbook of Chemistry, Handbook 

 Publishers Inc., Sandusky, Ohio. Italicized numbers indicate figures used in calculations. 



t Indicate most common form of the reagent. In addition, a calculation has been made 

 for the nearest lower and higher percentages as well. 



