MKP from a pet shop.
| IUPAC name
Potassium dihydrogen phosphate
| Other names
Potassium phosphate monobasic
|Molar mass||136.086 g/mol|
|Appearance||White crystalline powder|
|Melting point||252.6 °C (486.7 °F; 525.8 K)|
|Boiling point||400 °C (752 °F; 673 K) (decomposes)|
| 22.6 g/100 mL (20 °C)|
83.5 g/100 mL (90 °C)
|Solubility|| Slightly soluble in ethanol, methanol|
Insoluble in benzene, dichloromethane
|Safety data sheet||ScienceLab|
| Dipotassium phosphate|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Reacting MKP with 1 mole of potassium hydroxide will produce dipotassium phosphate, and further adding phosphoric acid will convert it to tripotassium phosphate:
- KH2PO4 + KOH → K2HPO4 + H2O
- K2HPO4 + KOH → K3PO4 + H2O
Potassium dihydrogen phosphate is a white solid, soluble in water. It decomposes when heated above 400 °C. MPK's density is 2.338 g/cm3 at standard conditions.
MKP is sold in some agricultural stores as fertilizer.
It can also be purchased from pet shops.
- Grow large crystals
- Make elemental phosphorus
MPK is safe to handle and poses little toxicity.
MKP doesn't require special storage and can be stored in any container.
MKP can be dumped in the ground or poured down the drain.