What is Monopotassium Phosphate CAS 7778-77-0?

Monopotassium phosphate, commonly called MKP, is the monobasic potassium salt of phosphoric acid with the formula KH2PO4. It is supplied as white crystals or powder and used as a water-soluble fertilizer, buffer and fermentation nutrient.

Why is MKP used in agriculture and fertigation?

MKP is a highly water-soluble source of both phosphorus and potassium with no nitrogen or sodium. Fertilizer-grade material is commonly labeled 0-52-34 and is used in foliar sprays, drip irrigation and soilless production during flowering, fruiting and root development.

Why is Monopotassium Phosphate useful as a pH buffer?

Monopotassium phosphate and its corresponding dipotassium salt form a classic phosphate buffer system. This helps maintain stable pH in biochemical, fermentation and analytical applications.

How soluble is MKP and what is its solution pH?

MKP dissolves readily in water, with solubility commonly cited around 22.6 g/100 mL at 20 C. A 1% solution is mildly acidic, typically around pH 4.3-4.8, which is useful for certain tank mixes and buffered formulations.

What are the main non-fertilizer applications of CAS 7778-77-0?

Beyond agriculture, MKP is used as a buffer, fermentation nutrient, food and beverage processing ingredient and chemical intermediate. Food or fermentation applications require a grade that meets the relevant purity and impurity limits.

Which specifications should I check before ordering Monopotassium Phosphate?

Confirm KH2PO4 content, P2O5, K2O, moisture, water-insoluble matter, chloride, iron, heavy metals and pH. Technical and agricultural water-soluble grades may have different impurity limits from food or fermentation grades.

Monopotassium Phosphate CAS 7778-77-0

Monopotassium Phosphate (MKP, KH₂PO₄), CAS 7778-77-0, is a high-purity water-soluble phosphorus and potassium fertilizer, buffer and fermentation nutrient supplied in tech and agricultural grades for foliar feeding, fertigation and industrial fermentation. Confirm the required grade, then request a quotation with COA/TDS/SDS for bulk supply.

CAS: 7778-77-0
Synonyms: Potassium dihydrogen phosphate, MKP, Potassium acid phosphate, Monobasic potassium phosphate
Einecs: 231-913-4
Molecular Formula: KH₂PO₄
Grade: Tech Grade / Agriculture Grade (Water Soluble)
Package: 25kg PP/PE woven bags, kraft paper bags, or 1000kg Jumbo bags (Customizable)

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Product Description

Monopotassium Phosphate, CAS 7778-77-0, also known as potassium dihydrogen phosphate or MKP, is the monobasic potassium salt of phosphoric acid KH₂PO₄; the EC/EINECS number is 231-913-4.

Synonyms: potassium dihydrogen phosphate; MKP; potassium acid phosphate; monobasic potassium phosphate.

CAS: 7778-77-0.

Molecular formula: KH₂PO₄.

Molecular weight: 136.09 g/mol.

EC number: 231-913-4.

It is a white, odorless crystalline powder or crystal that dissolves rapidly in water.

It is typically at least 99.0% KH₂PO₄, with about 51.5–52.0% P₂O₅ and at least 34.0% K₂O.

A 1% aqueous solution has a mildly acidic pH of about 4.3–4.8.

It is used in foliar sprays, drip irrigation, hydroponics and soilless production during flowering, fruiting and root development.

It is used as a buffering agent in biochemical, fermentation and analytical applications.

It is used as a fermentation nutrient and pH regulator in yeast, bacteria and microorganism culture.

It is used in food and beverage processing and as a chemical intermediate where an appropriate grade is specified.

Confirm KH₂PO₄ content, P₂O₅, K₂O, moisture, water-insoluble matter, chloride, iron, heavy metals and pH.

Store in tightly closed bags in a cool, dry, ventilated warehouse away from water and high humidity.

Keep bags sealed when not in use and store separately from toxic or hazardous materials.

Confirm packaging with the requested quantity and destination requirements.

The page is an RFQ entry point and does not state stock, price, MOQ or fixed lead time.

For an RFQ, state the intended use, required grade, quantity, packaging, destination and document needs.

FAQ - Technical & Supply Chain

Q:
What is Monopotassium Phosphate CAS 7778-77-0?

A: Monopotassium phosphate, commonly called MKP, is the monobasic potassium salt of phosphoric acid with the formula KH2PO4. It is supplied as white crystals or powder and used as a water-soluble fertilizer, buffer and fermentation nutrient.
Q:
Why is MKP used in agriculture and fertigation?

A: MKP is a highly water-soluble source of both phosphorus and potassium with no nitrogen or sodium. Fertilizer-grade material is commonly labeled 0-52-34 and is used in foliar sprays, drip irrigation and soilless production during flowering, fruiting and root development.
Q:
Why is Monopotassium Phosphate useful as a pH buffer?

A: Monopotassium phosphate and its corresponding dipotassium salt form a classic phosphate buffer system. This helps maintain stable pH in biochemical, fermentation and analytical applications.
Q:
How soluble is MKP and what is its solution pH?

A: MKP dissolves readily in water, with solubility commonly cited around 22.6 g/100 mL at 20 C. A 1% solution is mildly acidic, typically around pH 4.3-4.8, which is useful for certain tank mixes and buffered formulations.
Q:
What are the main non-fertilizer applications of CAS 7778-77-0?

A: Beyond agriculture, MKP is used as a buffer, fermentation nutrient, food and beverage processing ingredient and chemical intermediate. Food or fermentation applications require a grade that meets the relevant purity and impurity limits.
Q:
Which specifications should I check before ordering Monopotassium Phosphate?

A: Confirm KH2PO4 content, P2O5, K2O, moisture, water-insoluble matter, chloride, iron, heavy metals and pH. Technical and agricultural water-soluble grades may have different impurity limits from food or fermentation grades.

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