[Chemistry Class Notes] on Dipotassium Phosphate Pdf for Exam

What Is Dipotassium Phosphate?

Dipotassium Phosphate is an inorganic compound which is an extremely water-soluble salt. It is generally used as a fertiliser as it is a great source of potassium and phosphorus. It is also used as a food additive as a good source for potassium and phosphorus. It also finds its application as a buffering agent. Buffering agents are used to maintain the pH value of a solution near a particular chosen value. It is added during a chemical process so as to reduce the rapid change in the composition of the compound when acids or bases are added to it. There are different types of acid and base buffers like acetic acid, sodium acetate, sodium bicarbonate etc. 

Structure of Dipotassium Phosphate

The molecular formula or the dipotassium phosphate formula is: K2HPO4

The K2HPO4 name is also known as dipotassium hydrogen orthophosphate, potassium phosphate dibasic.

The picture below depicts the K2HPO4 structure: –

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Characteristics of Dipotassium Phosphate

• The IUPAC name of this compound is dipotassium hydrogen phosphate

• The density of Dipotassium Phosphate is 2.44g/cm3

• The K2HPO4 molecular weight or molar mass is 174.2g/mol 

• It accepts four hydrogen bonds 

• The melting point of this compound is greater than 465 °C

• The chemical formula of the compound is K2HPO4

• It is freely soluble in water 

• It is insoluble in ethanol 

• The production of K2HPO4 is done in the process of condensation of phosphoric acid using potassium hydroxide 

• As a result, Phosphoric acid is manufactured from the rock of phosphate, which is found commonly in several places around the globe. 

Physical Properties of Dipotassium Phosphate (K2HPO4)

• The Dipotassium Phosphate compound is odourless 

• The colour of the compound is white 

• It is a deliquescent solid which means that it tends to absorb moisture from the air and dissolve in it

• It is a three covalently bonded unit 

• The molecule of this compound has a heavy atom count of 7 

• The complexity of the compound is 4605 

• The compound can be easily soluble in water 

Chemical Properties of Dipotassium Phosphate (K2HPO4)

The compound Dipotassium Phosphate when reacts with hydrochloric acid, it forms potassium chloride and phosphoric acid. The chemical equation of the reaction is given below:  –

K2HPO4 + 2HCl → 2KCl + H3PO4

The compound dipotassium hydrogen phosphate when reacts with a base, sodium hydroxide it forms disodium hydrogen phosphate and water.

2NaOH + 3K2HPO4 → 2K3PO4 + 2H2O + Na2HPO4 

Uses of Dipotassium Phosphate

• Dipotassium phosphate is used in fertilisers. It is used as a component of fertilisers because of its highly water-soluble nature. It supplies the growing plants with a large percentage of phosphorus.

• It is used as a food additive. The grades of dipotassium hydrogen phosphate used in foods are different than that which are used in fertilisers. 

• It is added in milk to increase its pH. This is done in order to increase the net micelle charge. Micelles are aggregates of molecules. 

• It is used in the micelles as a competitive displacement of calcium by sodium.

Example Questions

Q1) Why is the Role of Phosphorus in Our Body? 

Phosphorus is quite responsible for enhancing the preservation, repair and restoration of healthy bones and teeth in your body. Phosphate is essential in their normal function in the context of muscular performance, and how effectively they contract.

Q2) Which Foods Contain Disodium Phosphate? 

Disodium phosphate is often used in food products, macaroni and pasta included. It is also used as an emulsifier in some cheeses. It can also be used in animal products, meat, canned sauces, Jell-O, milk evaporated and some chocolate.

Q3) What is the Role of Disodium Phosphate When it is Used as a Preservative? 

Dipotassium Phosphate (DKP) is an effective buffering agent for a range of balancing agent-functioning uses. Dipotassium Phosphate is highly effective in preventing coagulation when used as a food additive or preservative and is generally used as a buffering agent on the non-dairy creamer market.