C1152 Acid-Soluble Chloride in Concrete Help 1

[Scottmcl]

We are preparing to test concrete for chloride and I have some questions about the process. can someone help me to understand the blank determination process and the normality of the silver nitrate?

 

[Ron]

You can purchase 0.05N silver nitrate. I would suggest this approach, particularly if you do not have an analytical balance and precise volumetric dosing apparatus (pipettes, etc.).

As for the "blank" determination....the purpose is just to see if the process you are using can introduce chlorides into your procedure. Chlorides are common and can come from a variety of sources...for instance if you wash your lab equipment with tap water.

 

[Scottmcl]

Ron,
Thank you for the prompt response. My question about the blank is do I run it to its equivalence point as well? I believe that is the procedure. As far as the silver nitrate goes that is an excellent idea.

 

[Ron]

Yes. Run the blank completely.

 

[Scottmcl]

Ron,

I can't thank you enough for your help.
One last thing about the exact normalcy of the silver nitrate. The ASTM tells me to standardize with 5.00 mL 0.05 N NaCl diluted to 150 mL with water following the titration given in 8.1 beginning with the second sentence (without the sample). Would I run that all the way to the end as well and then calculate the normalcy of the silver nitrate based on the final amount used to reach equivalency? That is the way that I read the ASTM.

 

[Ron]

Yes, that is correct.

 

[Scottmcl]

Ron, your help has been invaluable. I wanted to make sure I read the ASTM correctly. Cheers!