Sodium Phosphate, Dibasic → Phosphoric Acid

HRID 1158546Notes

Reaction equation

HRID 1158546 reaction equation
[P:1]([O-:5])([O-:4])([OH:3])=[O:2].[Na+:6].[Na+]>O>[P:1]([O-:5])([O-:4])([OH:3])=[O:2].[Na+:6].[Na+:6].[P:1](=[O:2])([OH:5])([OH:4])[OH:3]

Participants

4

Reactant 1

HCID 24203Sodium Phosphate, Dibasic

Product 2

HCID 1004Phosphoric AcidHCID 24203Sodium Phosphate, Dibasic

Reagents, catalysts & solvents 1

HCID 962WaterSolvent4×

Procedure

Disodium hydrogenphosphate (secondary sodium phosphate), Na2HPO4, is a colorless, water-soluble crystalline salt. It exists anyhdrously and with 2 mol (density 2.066 gcm−3, water lost at 95°), 7 mol (density 1.68 gcm−3, melting point 48° with loss of 5 H2O), and 12 mol of water (density 1.52 gcm−3, melting point 35° with loss of 5 H2O); it becomes anhydrous at 100° and when more strongly heated transitions into the diphosphate Na4P2O7. Disodium hydrogenphosphate is produced by the neutralization of phosphoric acid with a soda solution using phenolphthalein as indicator. Dipotassium hydrogenphosphate (secondary or dibasic potassium phosphate), K2HPO4, is an amorphous white salt that is easily soluble in water.

Workup

  1. custombecomes anhydrous at 100°

Sources & evidence

ORD record
ord-2f4b2e6a04c640cdaa5abba2086b4669
Source dataset
uspto-grants-2010_10
Patent number
US07811076B2

Reaction notes

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