Patton Reeder's Reagent 25g Qualigens

About Patton Reeder's Reagent 25g Qualigens

• Catalogue Number: Q39812 (also Q39811 for another pack size)
• Synonyms: Patton and Reeder's Reagent, Calconcarbonic acid, 3-Hydroxy-4-(2-hydroxy-4-sulfo-1-naphthylazo)naphthalene-2-carboxylic acid
• Recommended Use: Laboratory chemical 
• Key Physical & Chemical Properties 
  • Appearance (Color/Form): Black to very dark purple powder or solid
  • Molecular Formula: C21H14N2O7SC sub 21 H sub 14 N sub 2 O sub 7 SC21H14N2O7S
  • Molecular Weight: 438.41 g/mol
  • CAS Number: 3737-95-9
  • Melting Point: Decomposes at approximately 300C
  • Solubility: Soluble in water, ethanol, and sodium hydroxide solutions
  • Storage Temperature: 2-30C (room temperature) 
  • Primary ApplicationThe main application is as an indicator for complexometric titrations: 
    • Used specifically for the determination of calcium in the presence of magnesium ions at a high pH (around pH 12).
    • The indicator changes color from blue (free indicator) to pink/red when it complexes with calcium ions; the color reverts to blue at the endpoint of the EDTA titration when all calcium has been bound by EDTA.