Baso4 Lewis Structure, Characteristics: 13 Facts You Should Know


BaSO4 is the chemical formula for Barium sulphate. It is the sulphate salts of barium metal which is alkaline and a divalent metal.

BaSO4 (barium sulphate) is the whitish or yellow small crystalline powder which has no odour. It is not soluble in water, R-OH groups and dilute acids, but soluble in hot concentrated H2SO4 (sulphuric acid). Its IUPAC name is barium (2+) sulphate. Molecular weight of barium sulphate is 233.39.

How to draw BaSO4 lewis structure?

To draw the barium sulphate i.e. BaSO4 lewis structure, we have to recognize that the barium is a metal and the SO4 (sulphate ion) is a non- metal also consider as a polyatomic ion. Metals and non- metals forms an ionic compound together. So, the metals get transfer their electrons to the non- metal part of the compound. Thus, the barium metal gets transfer their electrons to the sulphate ion.

So, to write the BaSO4 lewis structure, we have to write first Barium which is a metal and then we have to add the sulphate ion group next to which is a non- metal to the structure. The barium metal get transfer its electron to the sulphate ion non- metal. Barium metal belongs to the group two of the periodic table, thus it has two valence electrons in its valence shell. So, Barium transfers its 2 valence electrons to SO4 ion.

The electrons are negatively charged, so Ba transfers its two negative charges to SO4 ion. Due to which the two positive (2+) charge creates on Ba metal and the SO4 ion accepts the two electrons from Ba metal creates a two negative (2-) charge on SO4 ion. We have the brackets around SO4 ion to show the electron transfer from Ba to SO4 i.e. the Ba lost electrons and sulphate gain them, so they are not sharing electrons like we do in a covalent bond.

BaSO4 valence electrons

Barium metal belongs to the second group of the periodic table, so it has two valence electrons in its valence shell. Sulphur atom belongs to the 16th group of the periodic table so it has six electrons in its valence shell. Oxygen atom also belongs to the 16th group of the periodic table so it also has six valence electrons.

In SO4 ion, sulphur atom attached to the four oxygen atoms and also there is a 2- charge on SO4 ion, so the valence electrons for SO4 ion are:

Valence electrons SO42- = 6 (for S) + 6 x 4 (for O) + 2 (for 2-) = 32

Thus SO42- ion has total 32 valence electrons and Ba metal has two valence electrons, which it get shared with SO4 ion in BaSO4 lewis structure.

BaSO4 lewis structure formal charge

The formula to calculate the formal charge of any atom is:

Formal charge = (valence electrons – non-bonding electrons – ½ bonding electrons)

Ba metal has 2+ formal charges as it donates its two valence electrons to SO4 ion in BaSO4 lewis structure.

Also SO4 ion has 2- formal charge as it accepts two electrons from Ba metal in BaSO4 lewis structure.

In SO4 ion, central sulphur atom gets attached with four oxygen atoms with covalent bonds. So the formal charge for SO4 ion is as follows:

Formal charge for S atom = ( 6 – 0 – 8/2 ) = +2

Formal charge for O atom = ( 6 – 6 – 2/2 ) = -1

Formal charges on SO4 ion

BaSO4 lewis structure octet rule

Octet rule tells us about the presence of eight electrons in outer shell of any atom. Barium metal belongs to the 2nd group of the periodic table so it has two valence electrons in its outer valence shell orbital, as there are not eight electrons present in Ba atom so it has incomplete octet.

In SO4 ion, generally sulphur and oxygen atoms has complete octet as they both has eight – eight electrons, but with complete octet the SO4 ion has more formal charge on sulphur and oxygen atoms i.e. 2+ on S and -1 on each O atoms. By minimizing charge on two O atoms two double bonds creates on S atom making zero charge on S and two O atoms.

In that case S atom has 12 electrons, so it has extended octet and two O atoms has incomplete octet with six electrons while other two atoms has complete octet with -1 charge on it.

Octet rule for BaSO4 lewis structure

BaSO4 lewis structure lone pairs

BaSO4 lewis structure consists of both metal and non- metal compounds i.e. barium metal and SO4 ion is a non- metal which is a polyatomic ion. In BaSO4 lewis structure, there are only two electrons present on Ba metal as it belongs to the 2nd group of the periodic table. So, only lone electron pairs are present on Ba metal of BaSO4 lewis structure which it get shared with SO4 ion and creates 2+ charges on Ba metal and 2- charge on SO4 ion. The sharing of electrons is shown by the bracket around SO4 ion.

BaSO4 lewis structure shape

BaSO4 is an ionic compound as it contains SO4 polyatomic ion in it. Basically BaSO4 molecule does not have its own original shape as it is only and ionic compound and there is no bonding between Ba and SO4 ion, there is just sharing of electrons within the molecule. Thus BaSO4 lewis structure does not have any shape. Rather than SO4 ion has is basic shape as tetrahedral as central sulphur atom attached with four oxygen atoms.

BaSO4 lewis structure angle

BaSO4 molecule does not have any bond angle as there is no bond present within the molecule as it is originally an ionic compound with the presence of metal and non-metal moieties. But the SO4 ion has a bond angle of 109.50 degree within each S-O bonds due to the presence of double bonds repulsion creates between the ion and making the bond angle of 109.50 degree in SO4 ion.

BaSO4 lewis structure resonance

BaSO4 lewis structure does not show any resonance structure as there is not bonding between the BaSO4 molecules. Even it is an ionic molecule containing metal (Ba) and non- metal (SO4) compounds in it. But the SO4 ion can show various resonance structures, as it has double bonds and single bonds within S and O atoms and also it has lone electron pairs present on it. So, the resonance structure of BaSO4 ion is not possible but the resonance structure of only SO4 ion can possible.

BaSO4 hybridization

BaSO4 lewis structure does not show any hybridization as there is no mixing and recasting of atomic orbitals within the molecule, there is only sharing of electrons between Ba metal and SO4 ion creating 2+ charge on Ba and 2- charge on SO4 ion. But the only SO4 ion can have the sp3 hybridization as the central sulphur atom attached to the four oxygen atoms in SO4 ion.

BaSO4 solubility

BaSO4 (barium sulphate) is soluble in:

  • Hot sulphuric acid (H2SO4)

BaSO4 (barium sulphate) is insoluble in:

  • Water ( or hardly soluble)
  • R-OH group compounds
  • Dilute acids

Is BaSO4 ionic?

Yes, Barium sulphate (BaSO4) is an ionic compound. As there is no presence of covalent or pi bonds within the molecule. There is only presence of charges on Ba metal and SO4 ion which makes the BaSO4 an ionic compound.

Why BaSO4 ionic? As the Ba metal belongs to 2nd group of periodic table it contains only two valence electrons, which it get shared with the SO4 ion creating 2+ charge on Ba and 2- charge on SO4 ion as it accepts electrons from Ba. Due to the presence of charges on BaSO4 molecule it is ionic in nature.

How BaSO4 ionic? BaSO4 is an ionic compound and due to which it is insoluble in water due to presence of bigger ions. Ba2+ and SO42- both are bigger ions i.e. the bigger cation (Ba2+) stabilizes the bigger polyatomic anion (SO42-). Due to the sharing of electrons the BaSO4 being an ionic compound as cation and anion both present in it.

Is BaSO4 polar or nonpolar?

BaSO4 (barium sulphate) compound is polar in nature. Due to the presence of polar bonds with Ba and SO4 ion it is polar in nature, also the SO4 ion is also polar molecule and they cannot cancel out each other. Still BaSO4 is not soluble in polar solvent like water, due to the presence of strong crystals in BaSO4 molecule as water has weak dipole strength as compared to BaSO4.

Why BaSO4 polar? As BaSO4 is an ionic compound containing positively charged cation and negatively charged anion on it, which creates a dipole within the BaSO4 molecule which makes it polar.

How BaSO4 polar? Due to the presence of polar bon within positively charged Ba cation and negatively charged SO4 anion in BaSO4 molecule, there is the formation of polar bond within Ba and SO4 ion, makes it a polar compound.

Is BaSO4 acidic or basic?

BaSO4 is an salt and consider as neutral molecule generally. The salts are produced by the reaction between acids and bases. Thus, BaSO4 does not consider as acid or a base as it does not creates H+ and OH- ions in the water and even does not dissolve in it. But BaSO4 consists of both acidic part (Ba2+) and basic part (SO42-).

Why BaSO4 not acidic or basic? As BaSO4 is prepared with strong acid (H2SO4) and strong base (Ba(OH)2), so it have the Ba2+ acidic ion an SO42- basic ion, but it is neutral in nature as it is originally a salt in nature.

How BaSO4 is not acidic or basic? BaSO4 is polar in nature still is is not soluble in polar solvent like water and also does not creates H+ and OH- ions so it is a neutral molecule as BaSO4 is made up of strong acid and base.

Conclusion:

BaSO4 consists of two ions i.e. Ba2+ cation and SO42- anion. It is an ionic compound and has polar nature. BaSO4 is soluble in hot concentrated H2SO4. It is a neutral molecule.

Dr. Shruti Ramteke

Hello everyone I am Dr. Shruti M Ramteke, i did my Ph.D in chemistry. I have five years of teaching experience for 11-12 standard, B,Sc and MSc in chemistry subject. I have published total five research articles during Ph.D on my research work and i have fellowship from UGC for my Ph.D. My Masters with specilization Inorganic chemistry and my graduation with chemistry, zoology and environmental science subjects. thank You

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