The chemical formula for caustic soda is NaOH.
Physical Properties of Caustic Soda:
| Characteristic |
Details |
| Appearance |
White solid or flakes |
| Boiling Point |
1,388 °C (2,530 °F) |
| Crystal Structure |
Monoclinic or orthorhombic |
| Density |
2.13 g/cm³ |
| Electrical Conductivity |
High conductivity in aqueous solutions |
| Melting Point |
318.4 °C (605.1 °F) |
| Odor |
Odorless |
| pH |
Highly alkaline (typically pH 13-14) |
| Solubility |
Highly soluble in water |
Chemical Properties of Caustic Soda:
| Characteristic |
Details |
| Chemical Formula |
NaOH |
| Chemical Reaction with Water |
Exothermic reaction, produces heat |
| Corrosiveness |
Corrosive to metals, glass, and many materials |
| Decomposition |
Decomposes at high temperatures (>600 °C) |
| Ionization |
Dissociates into Na⁺ and OH⁻ ions in water |
| Neutralization |
Used for neutralizing acidic solutions |
| Reactivity |
Highly reactive with acids and acidic compounds |
| Reactivity with Organics |
Reacts with various organic compounds |
| Saponification |
Reacts with fats to produce soap |
Reaction of caustic soda with Alkali Metal
| Alkali Metal |
Reaction with Caustic Soda |
Chemical Equation |
| Lithium (Li) |
Forms lithium hydroxide and hydrogen gas |
2Li + 2NaOH react and convert into 2LiOH + H2 |
| Sodium (Na) |
Forms sodium hydroxide and hydrogen gas |
2Na + 2NaOH react and convert into 2Na2O + H2 |
| Potassium (K) |
Forms potassium hydroxide and hydrogen gas |
2K + 2NaOH react and convert into 2KOH + H2 |
| Rubidium (Rb) |
Forms rubidium hydroxide and hydrogen gas |
2Rb + 2NaOH react and convert into 2RbOH + H2 |
| Cesium (Cs) |
Forms cesium hydroxide and hydrogen gas |
2Cs + 2NaOH react and convert into 2CsOH + H2 |
| Francium (Fr) |
Reacts vigorously with water and caustic soda (NaOH) |
2Fr + 2H2O react and convert into 2FrOH + H2,
2Fr + 2NaOH react and convert into 2FrOH + 2Na + H2 |
Reaction of caustic soda with Alkaline Earth Metal
| Alkaline Earth Metal |
Reaction with Caustic Soda |
Chemical Equation |
| Beryllium (Be) |
Forms beryllium hydroxide and hydrogen gas |
2Be + 2NaOH react and convert into 2Be(OH)2 + H2 |
| Magnesium (Mg) |
Forms magnesium hydroxide and hydrogen gas |
Mg + 2NaOH react and convert into Mg(OH)2 + H2 |
| Calcium (Ca) |
Forms calcium hydroxide and hydrogen gas |
Ca + 2NaOH react and convert into Ca(OH)2 + H2 |
| Strontium (Sr) |
Forms strontium hydroxide and hydrogen gas |
Sr + 2NaOH react and convert into Sr(OH)2 + H2 |
| Barium (Ba) |
Forms barium hydroxide and hydrogen gas |
Ba + 2NaOH react and convert into Ba(OH)2 + H2 |
| Radium (Ra) |
Reacts vigorously with water and caustic soda (NaOH) |
Ra + 2H2O react and convert into Ra(OH)2 + H2,
Ra + 2NaOH react and convert into Ra(OH)2 + 2Na + H2 |
Reaction of caustic soda with Transition Metal
| Transition Metal |
Reaction with Caustic Soda |
Chemical Equation |
| Iron (Fe) |
Forms iron(II) hydroxide and hydrogen gas |
Fe + 2NaOH react and convert into Fe(OH)2 + H2 |
|
Alternatively, forms iron(III) hydroxide and hydrogen gas |
2Fe + 6NaOH react and convert into 2Fe(OH)3 + 3 H2 |
| Copper (Cu) |
Forms copper(II) oxide and water |
Cu + 2NaOH react and convert into CuO + H2O |
| Zinc (Zn) |
Forms zincate ion and hydrogen gas |
Zn + 2NaOH + 2H2O react and convert into Na2[Zn(OH)4] + H2 |
| Aluminum (Al) |
Forms sodium aluminate and hydrogen gas |
2Al + 2NaOH + 6H2O react and convert into 2Na[Al(OH)4] + 3 H2 |
| Nickel (Ni) |
Forms nickel(II) hydroxide and hydrogen gas |
Ni + 2NaOH react and convert into Ni(OH)2 + H2 |
| Chromium (Cr) |
Forms chromium(III) hydroxide and hydrogen gas |
2Cr + 6NaOH + 3H2O react and convert into 2Na3[Cr(OH)6] + 3 H2 |
| Manganese (Mn) |
Forms manganese(II) hydroxide and hydrogen gas |
Mn + 2NaOH react and convert into Mn(OH)2 + H2 |
Reaction of caustic soda with Non-Transition Metal
| Non-Transition Metal |
Reaction with Caustic Soda |
Chemical Equation |
| Aluminum (Al) |
Forms sodium aluminate and hydrogen gas |
2Al + 2NaOH + 6H2O react and convert into 2Na[Al(OH)4] + 3 H2 |
| Magnesium (Mg) |
Forms magnesium hydroxide and hydrogen gas |
Mg + 2NaOH react and convert into Mg(OH)2 + H2 |
| Calcium (Ca) |
Forms calcium hydroxide and hydrogen gas |
Ca + 2NaOH react and convert into Ca(OH)2 + H2 |
| Potassium (K) |
Forms potassium hydroxide and hydrogen gas |
2K + 2NaOH + 2H2O react and convert into 2Na+ + 2KOH + H2 |
| Sodium (Na) |
Forms sodium hydroxide and hydrogen gas |
2Na + 2NaOH react and convert into 2Na2O + H2 |
| Zinc (Zn) |
Forms zincate ion and hydrogen gas |
Zn + 2NaOH + 2H2O react and convert into Na2[Zn(OH)4] + H2 |
| Tin (Sn) |
Forms stannate ion and hydrogen gas |
Sn + 2NaOH + 2H2O react and convert into Na2[Sn(OH)6] + H2 |
| Lead (Pb) |
Forms plumbate ion and hydrogen gas |
Pb + 4NaOH + O2 react and convert into Na2PbO2 + 2H2O |
| Bismuth (Bi) |
Forms bismuthate ion and hydrogen gas |
Bi + 2NaOH + 2H2O react and convert into Na2BiO3 + 3 H2 |
Reaction of caustic soda with Metalloid
| Metalloid |
Reaction with Caustic Soda |
Chemical Equation |
| Boron (B) |
Forms boric acid and sodium borate |
B2O3 + 6NaOH + 9H2O react and convert into 2Na3BO3 + 9H2O |
| Silicon (Si) |
Forms sodium silicate and hydrogen gas |
Si + 2NaOH + 2H2O react and convert into Na2SiO3 + 3 H2 |
| Arsenic (As) |
Forms sodium arsenate and hydrogen gas |
2As + 6NaOH + 3H2O react and convert into 2Na3AsO4 + 3 H2 |
| Germanium (Ge) |
Forms sodium germanate and hydrogen gas |
Ge + 2NaOH + 2H2O react and convert into Na2GeO3 + 3 H2 |
| Antimony (Sb) |
Forms sodium antimonate and hydrogen gas |
Sb + 6NaOH + 3H2O react and convert into 2Na3SbO4 + 3 H2 |
Reaction of caustic soda with Non-metal
| Non-metal |
Reaction with Caustic Soda |
Chemical Equation |
| Carbon (C) |
Forms sodium carbonate and hydrogen gas |
C + 2NaOH react and convert into Na2CO3 + H2 |
| Nitrogen (N) |
Forms sodium nitrite and ammonia gas |
2NaOH + N2O react and convert into NaNO2 + NH3 + H2O |
| Phosphorus (P) |
Forms sodium phosphate and hydrogen gas |
P4 + 20NaOH + 20H2O react and convert into 4Na3PO4 + 10 H2 |
| Sulfur (S) |
Forms sodium sulfide and hydrogen sulfide gas |
S + 2NaOH react and convert into Na2S + H2S |
| Chlorine (Cl) |
Forms sodium hypochlorite and salt |
2NaOH + Cl2 react and convert into NaCl + NaClO + H2O |
Reaction of caustic soda with Lanthanide
| Lanthanide |
Reaction with Caustic Soda |
Chemical Equation |
| Lanthanum (La) |
Forms lanthanum hydroxide |
2NaOH + La(NO3)3 react and convert into La(OH)3↓ + 3NaNO3 |
Reaction of caustic soda with Actinide
| Actinide |
Reaction with Caustic Soda |
Chemical Equation |
| Uranium (U) |
Forms uranium hydroxide |
2NaOH + UO2(NO3)2 react and convert into U(OH)4↓ + 2NaNO3 + H2O |
