BUFFER SOLUTIONS 



525 



pK Ranok 4-49-918 

 Indicator, B.D.H. (Universal). 

 More accurate determinations may be made with (jne of the indicators 



given ill the next section. 



T. pH Range 2-2-3-9 



Vl'Ace 50 c.c. of solution (i.) in a number of flasks, add a drop of either 

 thymol blue or brom-phenol blue to each and various amounts of solution (v.) 

 as under : 



Make each up to 200 c.c. with distilled water. 



II. pB. Range 4-6-3 



To 50 c.c. of solution (i.) add a drop of either brom-phenol blue, methyl red 

 or brom-cresol purple, and the number of cubic centimetres of solution (iv.) 



