Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here





How can i find the acutal amount of mg/L after i titrate? I know how much NaOH I am suppose to add to get the correct titration. But how do I find mg/L?
I have a tank with water. I am adding phoshpate and I test the concnetration with a hand titrator. I use a indicator. I get an amount of NaOH added. How do I know the mg/L?
Can someone help me please? I have not had quant in about 4 years and i cant remember how to do it.

RE: concnetration

you are determine phosphate with NaOH? dont understand??

1. Said me the type of kit that you are using??
2. if the stequiometric relation behind NaoH and Phosphate is = 1. ppm PHOSP= ml NaOH added*Conc of NaOH* PMolecular of PHOSP/Sample volume.


Manuel Arguelles
Quality Analist

RE: concnetration

i am titrating with NaOH. I am not using a kit, I am using a hand tirator.
I have water in a tank. I am adding a power phoshpate to the tank. I take a 10ml sample from the tank. Adding pheynthaline to the sample and then adding NaOH until a color change to pink. So how do I know how much phosphate is in the sample?
I am trying to explaine it.
Thanks for responding,

RE: concnetration

Phosphates are not determined by NaOH addition to a Phenopthalein end point. Invest $20 or so in a phosphate analysis kit available at most pool and spa stores, or on-line at various retailers, that will give you a reasonably accurate value. Depending on the phosphate level you are working with, a significant dilution of the sample with bottled water (for example) may be required to test within the upper limits of the phosphate kit, then back calculating to the original sample (e.g. 1 part sample, 9 parts water = 10X multiplication factor).


Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close