Which reagent grade would you use to prepare a primary standard for titrimetric analysis?

Question

1. Technical grade.
2. Reagent grade is not important
3. Analytical reagent (AR) grade
4. General lab grade.

Answer 1

You would definitely want to use 3., analytical reagent grade.

For a primary standard, you need 99.99% or better purity. Otherwise, you can throw off the results of your analysis.

Answer 2

3. In fact, I think that AR is a trademark of a laboratory supply house.