PHENOLDISULPHONIC ACID SOLUTION 25%
PHENOL DISULPHONIC ACID is a product provided by Research-Lab Fine Chem Industries. Laboratory reagents are chemicals which are used in laboratories as a part of experimental procedures. PHENOL DISULPHONIC ACID is a 25% weight/volume solution in sulphuric acid.
Phenoldisulphonic acid was prepared by dissolving 25g of phenol in 150ml of conc. H2SO4. 35ml of fuming H2SO4 (30% SO3) was added and the solution was heated at 100ºC for 2 hours on water bath.
Nitrate reacts with phenoldisulphonic acid (PDA) to produce a nitro derivative, which in alkaline solution develops a yellow colour. ... The colour produced follows Beer's law and is proportional to the concentration of NO3- present in the sample.