Borax [Chemical formula, Physical, Chemical Properties and Reactions]

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

The chemical formula of borax is Na2B4O7·10H2O.

Physical Properties of Borax:

Properties Details
Appearance White crystalline solid
Boiling Point Decomposes at high temperatures
Crystal Structure Monoclinic
Density 1.73 g/cm³
Electrical Conductivity Poor conductor of electricity
Hardness 2 – 2.5 (Mohs scale)
Melting Point 741 °C (1,366 °F)
Odor Odorless
Solubility Soluble in water
Thermal Conductivity Low thermal conductivity
Transparency Transparent to translucent

Chemical Properties of Borax:

Properties Details
Chemical Formula Na2B4O7·10H2O (Sodium borate decahydrate)
pH Alkaline (pH ~9)
Hygroscopicity It readily absorbs moisture from the air.
Decomposition Decomposes when heated, releasing water and forming sodium metaborate, anhydrous borax, and boric acid.
Reactivity with Acids Reacts with acids to form boric acid and a corresponding salt.
Reaction with Metals Can form complexes with certain metals, such as borax bead test for identification of metal ions.
Flame Color Test Gives a green flame color when heated in a flame due to the presence of boron.
Reducing Agent It acts as a reducing agent in certain chemical reactions.
Complex Formation Can form complexes with various compounds and ions.
Glass Formation Borax is used in glass production as a flux to lower the melting point and improve the glass quality.

Reaction of borax with Alkali Metal

Alkali Metal Reaction with Borax
Lithium (Li) 2 Li + Na2B4O7·10H2O → 2 NaLiB4O7 + H2
Sodium (Na) 2 Na + Na2B4O7·10H2O → 4 Na2B4O7 + H2
Potassium (K) 2 K + Na2B4O7·10H2O → 2 KNaB4O7 + H2
Rubidium (Rb) 2 Rb + Na2B4O7·10H2O → 2 RbNaB4O7 + H2
Cesium (Cs) 2 Cs + Na2B4O7·10H2O → 2 CsNaB4O7 + H2
Francium (Fr) 2 Fr + Na2B4O7·10H2O → 2 FrNaB4O7 + H2

Reaction of borax with Alkaline Earth Metal

Alkaline Earth Metal Reaction with Borax
Beryllium (Be) 2 Be + Na2B4O7·10H2O → 2 NaBeB4O7 + H2
Magnesium (Mg) 2 Mg + Na2B4O7·10H2O → 2 NaMgB4O7 + H2
Calcium (Ca) 2 Ca + Na2B4O7·10H2O → 2 NaCaB4O7 + H2
Strontium (Sr) 2 Sr + Na2B4O7·10H2O → 2 NaSrB4O7 + H2
Barium (Ba) 2 Ba + Na2B4O7·10H2O → 2 NaBaB4O7 + H2
Radium (Ra) 2 Ra + Na2B4O7·10H2O → 2 NaRaB4O7 + H2

Reaction of borax with Transition Metal

Transition Metal Reaction with Borax
Iron (Fe) Fe + Na2B4O7·10H2O → NaFeB4O7 + H2
Copper (Cu) 2 Cu + Na2B4O7.10H2O → 2 NaCuB4O7 + H2
Zinc (Zn) Zn + Na2B4O7·10H2O → NaZnB4O7 + H2
Nickel (Ni) 2 Ni + Na2B4O7·10H2O → 2 NaNiB4O7 + H2
Cobalt (Co) Co + Na2B4O7·10H2O → NaCoB4O7 + H2
Chromium (Cr) Cr + Na2B4O7·10H2O → NaCrB4O7 + H2
Manganese (Mn) 3 Mn + 2 Na2B4O7·10H2O → 3 Na2MnB4O7 + 2 H2
Titanium (Ti) 2 Ti + 3 Na2B4O7.10H2O → 2 Na2TiB4O7 + 3 H2
Vanadium (V) 2 V + 3 Na2B4O7·10H2O → 2 Na2VB4O7 + 3 H2
Molybdenum (Mo) 3 Mo + 4 Na2B4O7·10H2O → 2 Na6Mo2B8O27 + 4 H2
Tungsten (W) W + 4 Na2B4O7·10H2O → Na4W2B12O31 + 4 H2
Silver (Ag) Ag + Na2B4O7·10H2O → NaAgB4O7 + H2
Gold (Au) 2 Au + 3 Na2B4O7·10H2O → 2 Na3AuB4O7 + 3 H2

Reaction of borax with Non-Transition Metal

Non-Transition Metal Reaction with Borax
Aluminum (Al) 2 Al + 3 Na2B4O7·10H2O → 3 NaAlB4O7 + 3 H2
Magnesium (Mg) Mg + Na2B4O7·10H2O → NaMgB4O7 + H2
Calcium (Ca) Ca + Na2B4O7·10H2O → NaCaB4O7 + H2
Sodium (Na) 2 Na + Na2B4O7·10H2O → 4 Na2B4O7 + H2
Potassium (K) 2 K + Na2B4O7·10H2O → 2 KNaB4O7 + H2
Lithium (Li) 2 Li + Na2B4O7·10H2O → 2 NaLiB4O7 + H2
Beryllium (Be) 2 Be + Na2B4O7·10H2O → 2 NaBeB4O7 + H2
Barium (Ba) 2 Ba + Na2B4O7·10H2O → 2 NaBaB4O7 + H2
Strontium (Sr) 2 Sr + Na2B4O7·10H2O → 2 NaSrB4O7 + H2
Radium (Ra) 2 Ra + Na2B4O7·10H2O → 2 NaRaB4O7 + H2
Aluminum (Al) 2 Al + 3 Na2B4O7·10H2O → 3 NaAlB4O7 + 3 H2
Gallium (Ga) 2 Ga + 3 Na2B4O7·10H2O → 2 NaGaB4O7 + 3 H2
Indium (In) 2 In + 3 Na2B4O7·10H2O → 2 NaInB4O7 + 3 H2
Thallium (Tl) 2 Tl + 3 Na2B4O7·10H2O → 2 NaTlB4O7 + 3 H2

Reaction of borax with Non-Metal

Non-Metal Reaction with Borax
Hydrogen (H) 2 H2 + Na2B4O7·10H2O → 4 NaBO2 + 9 H2O
Carbon (C) C + 2 Na2B4O7·10H2O → Na2B4O7+ Na2CO3 + CO2 ↑ + 10 H2O
Nitrogen (N) 4 NH4 + Na2B4O7·10H2O → Na2B4O7 + 4 NaOH + 8 H2O + N2
Oxygen (O) 4 Na2B4O7·10H2O → 2 Na2B8O13 + 13 H2O + 3 O2
Phosphorus (P) 2 P4 + 15 Na2B4O7·10H2O → 14 NaBO2+ Na3PO4 + 30 H2O
Sulfur (S) 8 S + 15 Na2B4O7·10H2O → 15 NaBO2+ Na2S2O3 + 30 H2O
Fluorine (F) 2 F2 + 4 Na2B4O7·10H2O → 8 NaBO2+ 2 NaBF4 + 20 H2O + O2
Chlorine (Cl) 4 Cl2 + 8 Na2B4O7·10H2O → 16 NaBO2+ 2 Na2B6O10Cl2 + 40 H2O + O2
Bromine (Br) 4 Br2 + 8 Na2B4O7·10H2O → 16 NaBO2+ 2 Na2B6O10Br2 + 40 H2O + O2
Iodine (I) 4 I2 + 8 Na2B4O7·10H2O → 16 NaBO2+ 2 Na2B6O10I2 + 40 H2O + O2 ↑

Reaction of borax with Metalloid

Metalloid Reaction with Borax
Boron (B) 2 B + 3 Na2B4O7·10H2O → Na2B4O7 + 6 NaBO2+ 6 H2
Silicon (Si) 2 Si + Na2B4O7·10H2O → Na4SiO4 + 5 NaBO2+ 10 H2
Germanium (Ge) 2 Ge + Na2B4O7·10H2O → Na4GeO4 + 5 NaBO2+ 10 H2
Arsenic (As) 2 As + 5 Na2B4O7·10H2O → Na4AsO4 + 5 NaBO2+ 10 H2
Antimony (Sb) 2 Sb + 5 Na2B4O7·10H2O → Na4SbO4 + 5 NaBO2+ 10 H2
Tellurium (Te) 2 Te + 5 Na2B4O7·10H2O → Na4TeO4 + 5 NaBO2+ 10 H2
Polonium (Po) 2 Po + 5 Na2B4O7·10H2O → Na4PoO4 + 5 NaBO2 + 10 H2

 

 

All Copyrights Reserved 2025 Reserved by T4Tutorials