Chemical Forums
Chemistry Forums for Students => Analytical Chemistry Forum => Topic started by: denisa174 on March 22, 2021, 05:37:20 AM
-
Hello,
I have a question about purity of a standard. I need to buy a formic acid. I've found 99% (acidimetric) and 99% (alkalimetric) pure acids. What does "alkali-, acidimetric" here mean? Is that a method of determination of the purity or is it anything else?
Next question about the formic acid is: Do you have some tip for CE standard?
Thanks
-
Its the method by titration.
-
Its the method by titration.
Using titration to determine main component is a rather poor approach.
Assume you go 99.9% with titration error three orders of magnitude lower, so 99.9±0.1%. Does it tell you anything about amount of impurities?
Now assume you got the impurity as 0.1% with - again - an error three orders of magnitude lower, so 0.1±0.0001%. Do you see why this information is much better?
-
I think it didnt tell about impurities. It tell about the grade. Its 50, 80 or 99 % HCOOH. For impurities need other methods like HPLC,IR UV/Vis, AAS for metals, etc.
-
The 99% grade is given, no need to check it.
-
I think here is a misunderstanding. The question was 99% acidimetric, what does it mean? It means it was determined by a titration isnt it. Of course normaly it hasnt to be checked,