Carbon Tetrabromide(CBr4) Properties (25 Complete Facts)

Carbon tetrabromide is a colorless crystalline compound having one carbon and four bromine atoms. Let us discuss the physical and chemical properties of CBr4.

Carbon in CBr4 is sp3 hybridized and it possesses a tetrahedral structure with a bond angle of 109.50. It is much denser than water and soluble in ethanol, chloroform, and ether but almost insoluble in water (0.024 g/100 mL at 300 C). It is more unstable than the other tetrahalomethanes (CCl4, CI4, CF4).

Let us focus on the IUPAC name, polarity, melting point, boiling point, radius, reactions, and many more relevant discussions on CBr4.

Carbon Tetrabromide IUPAC Name

The IUPAC (International Union of Pure and Applied Chemistry) name of carbon tetrabromide is carbon tetrabromide itself. Carbon is the central atom and bromine is in a -1 oxidation state. Therefore, bromine is written as bromide.

Carbon Tetrabromide Chemical Formula

Carbon tetrabromide has the chemical formula CBr4. There is a covalent interaction between carbon and each of the four bromine atoms.

Carbon Tetrabromide CAS Number

Carbon tetrabromide has the CAS registry number (authentic numeric identifier which can contain up to 10 digits) 558-13-4.

Carbon Tetrabromide Chem Spider ID

Carbon tetrabromide has the ChemSpider (ChemSpider is a free chemical structure database) ID 10732.

Carbon Tetrabromide Chemical Classification

  • Carbon tetrabromide can be chemically classified as an inorganic crystal compound
  • Carbon tetrabromide can be chemically classified as a neutral compound (neither alkaline nor acidic).
  • Carbon tetrabromide can be chemically classified as a covalent compound.
  • Carbon tetrabromide can be chemically classified as members of the tetrahalomethane group

Carbon Tetrabromide Molar Mass

The molar mass of carbon tetrabromide is 331.627 g. This molar mass is obtained from the summation of the molar mass of carbon and four bromine atoms which are 12.011 g/mole and 79.904 g/mole respectively.

Carbon Tetrabromide Color

Pure carbon tetrabromide is a colorless or yellow-brown crystalline solid compound.

Carbon Tetrabromide Viscosity

The viscosity of carbon tetrabromide cannot be measured as it is a solid and crystalline compound at room temperature.

Carbon Tetrabromide Molar Density

The molar density of carbon tetrabromide is 0.0103 mol/mL because it has a density of 3.42 g/ml and a molar mass of 331.672 g/mol.

Carbon Tetrabromide Melting Point

Carbon tetrabromide has a melting point of 94.50 C or 202.00 F.

Carbon Tetrabromide Boiling Point

The boiling point of carbon tetrabromide is 189.70 C or 373.40 F. But it undergoes a decomposition reaction at the temperature of 462.8 K.

Carbon Tetrabromide state at Room Temperature

At room temperature, carbon tetrabromide appears as a colorless to yellow-brown crystalline solid.

Carbon Tetrabromide Covalent Bond

Carbon tetrabromide is a covalently bonded molecule. There are four covalent bonds present in the structure of CBr4. All the C-Br bonds are equivalent, and they share their valence electron pairs mutually between them.

carbon tetrabromide properties
Covalent Bonds in CBr4

Carbon Tetrabromide Covalent Radius

The covalent radius of the sp3 hybridized carbon is 76 pm and bromine is 114 pm.

Carbon Tetrabromide Electron Configurations

Electron configuration is the placing of the revolving electrons in different orbitals or shells which are nothing but the energy states. Let us talk about it in detail.

Carbon tetrabromide has the electron configuration of carbon and four bromine atoms. Carbon and bromine both are p-block elements having the electron configuration of [He] 2s2 2p2 and [Ar] 4s2 3d10 4p5.

Carbon Tetrabromide Oxidation State

Carbon tetrabromide is in the oxidation number 0 because it is a neutral compound. Carbon is in +4 and each of the four bromine atoms is in a -1 oxidation state. Therefore, the total charge of CBr4 is 0.

Carbon Tetrabromide Acidity/Alkaline

Carbon tetrabromide is neither acid nor alkaline because the central carbon atom cannot accept or donate extra electron pairs due to having an octet-filled-up electron configuration.

Is Carbon Tetrabromide odorless?

Carbon tetrabromide has a slight but sweet odor.

Is carbon tetrabromide paramagnetic?

Unpaired electrons, attracted by the weak magnetic fields, in any molecule make a compound paramagnetic. Let us check whether carbon tetrabromide is paramagnetic or not.

Carbon tetrabromide is not paramagnetic due to the absence of unpaired electrons. Carbon in CBr4 is sp3 hybridized and all the electrons of carbon as well as bromine are paired up. Therefore, CBr4 is a diamagnetic compound.

Carbon Tetrabromide Hydrates

Carbon tetrabromide does not form any hydrates because there are no water molecules in the crystal of carbon tetrabromide. Besides that,  it is also sparingly soluble in water.

Carbon Tetrabromide Crystal Structure

The colorless crystal of CBr4 has two polymorphs crystalline II or β and crystalline I or α. Both of the crystal structure is monoclinic and have the space group C2/c with the lattice parameters a = 20.9 nm, b = 12.1 nm, c = 21.2 nm, and β = 110.50.

Carbon Tetrabromide Polarity and Conductivity

  • Carbon tetrabromide is a nonpolar molecule with zero dipole moment. But all the C-Br bonds are polar, but their relative arrangements cancel out the bond dipole moment and make CBr4 nonpolar.
  • Being a covalent organic molecule, CBr4 does not conduct electricity because it cannot be dissociated into its constituent ions.

Carbon Tetrabromide Reaction with Base

Carbon tetrabromide reacts with the organic base like

  • C9H7N (Quinoline)+CBr4 = C9H7N CBr4
  • C5H5N (Pyridine)+ 2(CBr4) = C5H5N (CBr4)2
  • C5H11N (piperidine)+ 2(CBr4) = C5H11N (CBr4)2
  • 4 C2H5NH2 (ethylamine)+CBr4 = (C2H5NH2)4 CBr4.

Carbon Tetrabromide Reaction with Acid

CBr4 reacts with mild acidic isopropanol and forms isopropyl halide and this reaction is known as the Appel reaction.

(CH3)2 CHOH + CBr4 + PPh3 = (CH3)2 CHBr + by product.

Carbon Tetrabromide Reaction with Metal

Argon gas undergoes a condensation reaction with the beams of lithium atoms after being diluted by carbon tetrabromide. This reaction produces infrared absorption, and this absorption is identified as lithium bromide and the tribromo methyl radical.

Ar (g)+Li (beam)+ CBr4 = Infrared (IR) absorption


Carbon tetrabromide is used as an organic solvent to dissolve greases, waxes, and oils in the plastic and rubber industry for vulcanization, and polymerization. It is also used as fire resistant due to its inflammable nature.

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