RXSOL
Test Kit For Water
Hardness Titration Solution - I
SKU: RXSOL-62-5531-001
Titration sol’n., (EDTA), 40 mg/L, 2 EPM, 8 oz
Application
EDTA solution is added to the ( indicator mixed with testing water ) solution and reacts with the free metal ions (those not bonded to the indicator). Since the metal-EDTA complexes are colorless, the solution still appears red.
EDTA continues to be added. After all the free metal ions are bound to the EDTA, the EDTA displaces the indicator, complexing the remaining metal ions until all metal ions are bound to EDTA. The red metal-indicator complex is no longer present and the indicator is free. The indicator is a weak acid and its color is dependent on how it is protonated:
