Citric acid [Chemical formula, Physical, Chemical Properties and Reactions]

By: Prof. Dr. Fazal Rehman Shamil | Last updated: February 3, 2024

The chemical formula of citric acid is C6H8O7.

Physical Properties of Citric Acid:

Properties Details
AppearanceWhite crystalline powder
Boiling PointDecomposes above 310 °C
Density1.665 g/cm³
Melting Point156-159 °C
OdorOdorless
SolubilityHighly soluble in water
TasteSour

Chemical Properties of Citric Acid

Properties Details
Acid-Base NatureWeak organic acid, acts as a tribasic acid (three ionizable protons)
BiodegradabilityBiodegradable under normal environmental conditions
Chelating AgentForms complexes with metal ions, such as calcium and iron
Chemical FormulaC₆H₈O₇
Molecular Weight192.13 g/mol
ReactivityReacts with alkalis and bases to form citrate salts
Reducing AgentCan undergo oxidation-reduction reactions

Reaction of citric acid with Alkali metal

Alkali metalReaction with citric acid
Lithium (Li)2C6H8O7 + 3LiOH    react and convert into  Li3C6H5O7 + 3H2O
Sodium (Na)3 C6H8O7 + 3NaOH    react and convert into  Na3C6H5O7 + 3H2O
Potassium (K)3 C6H8O7 + 3KOH    react and convert into  K3C6H5O7 + 3H2O
Rubidium (Rb)3 C6H8O7+ 3RbOH    react and convert into  Rb3C6H5O7 + 3H2O
Cesium (Cs)3 C6H8O7 + 3CsOH    react and convert into  Cs3C6H5O7 + 3H2O
Francium (Fr)No data available.

Reaction of citric acid with Alkaline earth metal

Alkaline earth metalReaction with citric acid
Beryllium (Be)3 C6H8O7 + Be(OH)2    react and convert into  Be3(C6H5O7)2 + 4H2O
Magnesium (Mg)3 C6H8O7 + Mg(OH)2    react and convert into  Mg3(C6H5O7)2 + 4H2O
Calcium (Ca)3 C6H8O7 + Ca(OH)2    react and convert into  Ca3(C6H5O7)2 + 4H2O
Strontium (Sr)3 C6H8O7+ Sr(OH)2    react and convert into  Sr3(C6H5O7)2 + 4H2O
Barium (Ba)3 C6H8O7 + Ba(OH)2    react and convert into  Ba3(C6H5O7)2 + 4H2O
Radium (Ra)No data available.

Reaction of citric acid with Transition metal

Transition metalReaction with citric acid
Iron (Fe)3 C6H8O7 + 2FeCl2    react and convert into  Fe3(C6H5O7)2 + 2HCl + 2H2O

3 C6H8O7 + 2FeCl3    react and convert into  Fe3(C6H5O7)2  + 6HCl

Copper (Cu)3 C6H8O7+ 2CuSO4    react and convert into  Cu3(C6H5O7)2  + 3H2SO4
Zinc (Zn)3 C6H8O7+ ZnSO4    react and convert into  Zn3(C6H5O7)2 + 3 H2SO4
Nickel (Ni)3 C6H8O77 + 2NiSO4    react and convert into  Ni3(C6H5O7)2 + 3 H2SO4
Chromium (Cr)3 C6H8O77 + 2CrCl3    react and convert into  Cr3(C6H5O7)2 + 6HCl
Manganese (Mn)3C6H8O7 + MnSO4    react and convert into  Mn3(C6H5O7)2 + 3 H2SO4
Cobalt (Co)3 C6H8O77 + 2CoCl2    react and convert into  Co3(C6H5O7)2 + 2HCl + 2H2O
Titanium (Ti)C6H8O7+ TiO2 + 2H2O    react and convert into  Ti(C6H5O7)2 + 2H2O

Reaction of citric acid with Non-transition metal/non-metal

Non-transition metal/non-metalReaction with citric acid
Carbon (C)C6H8O7+ C    react and convert into  C5H4O3CO2 + CO2 + 2H2O
Sulfur (S)C6H8O7+ 2S    react and convert into  H2S + 2SO2 + 2H2O
Phosphorus (P)C6H8O7+ P    react and convert into  P4O10 + 10H2O

Reaction of citric acid with Non-metal

Non-metalReaction with citric acid
Chlorine (Cl)C6H8O7+ Cl2    react and convert into  various products
Hydrogen (H)C6H8O7+ H2    react and convert into  C6H14N2O3
Sulfur (S)C6H8O7+ 2S    react and convert into  H2S + 2SO2 + 2H2O

Reaction of citric acid with Metalloid

MetalloidReaction with citric acid
Boron (B)C6H8O7 + 3B2O3    react and convert into  2B(OH)3 + 3CO2
Silicon (Si)C6H8O7+ 3SiO2    react and convert into  C4H4O2 + 3CO2 + 3SiO2