concnetration

[cmwatson78]

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.
Thanks

 

[arguellesmanuel]

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.

Bye.


CHEM. TeCh
Manuel Arguelles
Quality Analist
Venezuela

 

[cmwatson78]

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,
Cheri

 

[orenda1168]

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).

Orenda