
plating, anodizing, & finishing Q&As since 1989
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Nitric acid analysis in chromating solution
May 28, 2010
hello to all,
can any one please give me the method for analysis of Nitric acid (
65% )in yellow chromating solution we are facing a big problem in maintaining the nitric acid in yellow chromating solution as we are new to this process
Thank you.
plater - Bangalore, India
June 1, 2010
The OEM for the chromating solution will be happy to provide that information. If you have a home brew, then you will have a problem establishing a value to test to as the tank solution ages.
James Watts- Navarre, Florida
August 7, 2010
1. 5 mL sample of bath in a 250 mL Erlenmeyer flask.
2. 75 mL DI water.
3. 5 drops phenolphthalein indicator.
4. titrate against 1.0N sodium hydroxide solution. color change will be pale orange to dark pink-red.
v/v% HNO3 = mL 1.0N NaOH x 1.43

Randall Fowler - Fowler Industrial Plating, LLC
Cleveland, Tennessee, USA
February 27, 2011
I believe you can do this testing through an automated thermotitration. It easy and very accurate.
Tony Paulin- Bardstown, Kentucky, USA
