Dipotassium hydrogenphosphate
[CAS 7758-11-4]

Identification

• Classification: API >> Water, electrolyte and acid-base balance regulator >> Acid-base balance regulator
• Name: Dipotassium hydrogenphosphate
• Synonyms: Potassium phosphate dibasic
• Molecular Formula: K₂HPO₄
• Molecular Weight: 174.17
• CAS Registry Number: 7758-11-4
• EC Number: 231-834-5
• SMILES: OP(=O)([O-])[O-].[K+].[K+]

Properties

• Melting point: 465 (Decomposes) °C (Expl.)
• Solubility: Soluble in water (Expl.)

Safety Data

• Hazard Symbols: GHS05;GHS07 Danger
• Risk Statements: H315-H318
• Safety Statements: P264-P264+P265-P280-P302+P352-P305+P354+P338-P317-P321-P332+P317-P362+P364

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin irritation	Skin Irrit.	2	H315
Serious eye damage	Eye Dam.	1	H318
Acute toxicity	Acute Tox.	4	H302
Skin corrosion	Skin Corr.	1A	H314
Eye irritation	Eye Irrit.	2	H319

chemBlink Chemical Story

Dipotassium hydrogenphosphate matters because dipotassium hydrogen phosphate supplies HPO4(2-) for potassium phosphate buffers, translating the Henderson-Hasselbalch relationship into routine laboratory practice. This connection between molecular structure and observable behavior is more informative than a simple list of uses. CAS 7758-11-4 identifies the substance in this chemBlink record, while its practical significance comes from the way its functional groups, composition, or material structure control reactivity and physical properties.

The broader lesson is that chemical identity alone does not determine performance. Conditions such as pH, temperature, formulation, concentration, molecular distribution, or biological environment can decide whether the same underlying chemistry is useful, inactive, or hazardous. For chemists, Dipotassium hydrogenphosphate is therefore a useful case study in connecting molecular-scale behavior with a real laboratory, industrial, biological, or materials-science outcome.

References: CAS/PubChem identity records, CAS 7758-11-4; analytical chemistry references

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