区别Anhydrous and Monohydrate Citric Acid

Thekey difference在无水和一水合物柠檬酸之间是anhydrous citric acid has no water ofcrystallizationwhereas the monohydrate citric acid has a water molecule associated with one citric acid molecule.

Citric acidis a weak organic acid, thus, we can find it naturally in the citrus fruits. Manufacturers produce a high amount of citric acid per year because it has many uses; as an acidifier, as a flavouring andchelating agent. This compound can exist as either the anhydrous form (free of water) or as the monohydrate form.

CONTENTS

1.Overview and Key Difference
2.What is Anhydrous Citric Acid
3.What is Monohydrate Citric Acid
4.并排比较 - 表格形式无水与一水合物柠檬酸
5.概括

What is Anhydrous Citric Acid?

Anhydrous citric acid is the water-free form of citric acid. The appearance of this compound is colorless, and it is odorless. It has no water in its dry, granulated form. We can produce this compound via crystallization from hot water.

The anhydrous citric acid forms from the monohydrate form at 78 °C. The density of the anhydrous form is 1.665 g/cm3. It melts at 156 °C, and the boiling point of this compound is 310 °C. The chemical formula of this compound is C₆H₈O₇while the molar mass is 192.12 g/mol.

What is Monohydrate Citric Acid?

Monohydrate citric acid is the water-containing form of citric acid. It has one water molecule associated with one citric acid molecule. We call this water as water of crystallisation. This form of citric acid forms via the crystallization from cold water.

The monohydrate form converts into the anhydrous form at 78 °C. The density of this compound is 1.542 g/cm3. The chemical formula of this compound is C₆H₈O₇.H₂O, and the molar mass is 210.138 g/mol. The melting point is 135 °C, and the boiling point is 310 °C.

What is the Difference Between Anhydrous and Monohydrate Citric Acid?

Anhydrous citric acid is the water-free form of citric acid but, the monohydrate citric acid is the water-containing form of citric acid. This is the main difference between anhydrous and monohydrate citric acid. Furthermore, the chemical formula of anhydrous citric acid is C₆H₈O₇. The molar mass of this compound is 192.12 g/mol. We can produce this compound via crystallization from hot water. On the other hand, the chemical formula of monohydrate citric acid is C₆H₈O₇.H₂O, and the molar mass is 210.138 g/mol. In addition, we can produce this compound via crystallization from cold water.

概括– Anhydrous vs Monohydrate Citric Acid

Citric acid exists in two forms as anhydrous form and monohydrated form. The difference between anhydrous and monohydrate citric acid is that the anhydrous citric acid has no water of crystallization whereas the monohydrate citric acid has a water molecule associated with one citric acid molecule.

Reference:

1.特里，詹妮弗。“什么是无水柠檬酸？”Livestrong.com，Leaf Group，2017年10月3日。Available here
2. “Citric Acid Monohydrate.” National Center for Biotechnology Information. PubChem Compound Database, U.S. National Library of Medicine.Available here

Image Courtesy:

1.’Lemon-edit1’By André Karwath aka Aka – Own work,(CC BY-SA 2.5)viaCommons Wikimedia