Citric acid monohydrate
Molecular formula: C6H8O7.H2O.
Molecular weight: 210.14.
Properties: density 1.54. Melting point 135-152 ℃. Flash point of 173.9 ℃. Water solubility 1630 g / L (20 ℃).
Physical and chemical properties
Appearance: white crystalline powder, odorless.
Melting point (℃): 153.
Boiling point (℃): (decomposition).
Relative density (water = 1): 1.6650.
Flash point (℃): 100.
Ignition temperature (℃): 1010 (powder).
Explosion limit% (V / V): 8.0 (65 ℃).
Solubility: soluble in water, ethanol, ethyl ether, insoluble in benzene, slightly soluble in chloroform.
The main purpose
Main purposes: for spices or as acidifier beverages, food and medicine as a multivalent chelator, is also a chemical intermediate.
Note
Health hazards: a stimulating effect. In industrial use, the contact may cause eczema. Explosion hazard: can burn, with irritation.
Hazardous characteristics: powder can form explosive mixtures with air. In case of fire, heat or contact with oxidants, combustion caused a risk of explosion of water with citric acid and sodium citrate dihydrate ph6.0 of citrate buffer.
As the pH 6, buffer pair is the disodium salt and trisodium salt (citric acid Ka1 = 7.4 × 10 ^ -4, Ka2 = 1.7 × 10 ^ -5, Ka3 = 4.0 × 10 ^ -7).