-- The Home Page of the Finishing Industry
23+ years of serious education, promoting Aloha,
& the most fun you can have in metal finishing smiley
    no popups, no spam
on this site
current topics
topic 8976

Sodium hydroxide analysis of alkaline zinc


What indicator do you suggest I use for analysis of sodium hydroxide in alkaline non cyanide zincs? The one used at present is BDH 11-13 but this is no longer available.

Philip Gormley
plating services - Irvine ,Ayrshire, Scotland


Try using Sulfo-orange or phenolpthalein. I use the sulfo-orange for cyanide based solutions. It might work. I use the phenolpthalein for alkaline cleaners.

I'm not at work until Tuesday, at which time, if you want I can try a couple of experiments and get back to you.

K. Gendron
- Trenton, ON, Canada


1. 5 ml. sample into a 250 ml. flask.

2. Add 25 ml. 20 % barium carbonate.

3. Add 3 drops phenolphthalein indicator.

4. Titrate with 0.1 N hydrochloric acid, color change is pink to white.

5. mls. titrated x 1.06 = oz/gal.

Bill Hemp
tech svc. w/ chemical supplier - Grand Rapids, Michigan


In response to the NaOH Titration procedure of Alkaline Zinc At our shop we use 5 ml sample 20 ml water A few specks of Indigo Carmine Indicator Titrate with 1.0N HCl from yellow to blue mls titrated * 0.95 = OZ/GAL * 7.5 = gms/lt

Lee Moss
- Calgary, Alberta, CANADA


We gave up on indicators and now use a pH meter and stirrer this gives more repeatable results. End point pH 11.2

Martin Trigg-Hogarth
Martin Trigg-Hogarth
surface treatment shop - Stroud, Glos, England

This public forum has 60,000 threads. If you have a question in mind which seems off topic to this thread, you might prefer to Search the Site

ADD a Comment to THIS thread START a NEW threadView CURRENT TOPICS

Disclaimer: It's not possible to diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations may be deliberately harmful.

  If you need a product/service, please check these Directories:

JobshopsCapital Equip. & Install'nChemicals & Consumables Consult'g, Train'g, SoftwareEnvironmental ComplianceTesting Svcs. & Devices

©1995-2018, Inc., Pine Beach, NJ   -   About   -  Privacy Policy
How Google uses data when you visit this site.