# Does Hach offer a test kit for testing percent (%) acid or base?

## Document ID

Document ID TE3560

## Published Date

Published Date 25/01/2018
Question
Does Hach offer a test kit for testing percent (%) acid or base?
Summary
Titration for percent acid/base.
Hach does not offer a kit for testing percent acid/base. Everything that would be required to do a titration for total acid or base is available but would need to be purchased seperately, not as a kit. Method 8200/8233 is/are the method(s) to follow. Results will be given in meq/L which can be converted to percent acid/base with a simple calculation, so long as the molecular weight (MW) for the acid or base being calculated for is known.

1000 meq= 1 eq
MW g=  1 eq
10 g/L= 1 %

(1 meq/L) * (1 eq/ 1000 meq) * ( MW g/eq) * (1 %/ 10 g/L) = MW/10,000 %

So to convert results from meq/L to percent, multiply result by the MW, then divide by 10,000.

Example: Result is 4000 meq/L from doing an Acid titration following Method 8200. It is needed to get that result in % HCl. The Molecular weight for HCl is 36.46 g/mol.

(4000*36.46)/10000= 14.58 %

NOTE: There  would be an additional step for polyprotic acids/bases (like Sulfuric Acid H 2SO 4 or Calcium Hydroxide Ca(OH) 2). Divide by the final result by the number of protons that acid has or that base accepts (for example 2 for Sulfuric Acid or Calcium Hydroxide).