SnCl2 Lewis Structure: Drawings, Hybridization, Shape, Charges, Pair And Detailed Facts

In this article, “sncl2 lewis structure” drawing of SnCl2 lewis structure with hybridization, formal charge calculation, polarity and structure are discussed briefly.

Stannous chloride, SnCl2 is a white crystalline compound with molar mass 189.6 g/mol. Sn is sp2 hybridized with a bond angle 950 and Sn-Cl bond length 242 pm. SnCl2 is basically used as reducing agent. The structure of stannous chloride is angular or v-shaped with two bond pair and one lone pair.

Let’s focus on the following topics on SnCl2.

How to draw lewis structure for SnCl2?

Lewis structure is one type of structural representation of any molecule by which number of nonbonded as well as bonding electrons can be easily determined.

To draw the lewis structure of SnCl2, following steps should be kept in mind-

  • Valance electron of Sn and Cl will be counted first because determining the number of valance electron will help to count the nonbonding and bonded electrons. Sn and Cl have four and seven electrons in their valance shell respectively.
  • Now it is the time to count the bond connectivity present in the molecule. Sn is the central atom and it is attached with two chlorine atoms by two covalent bonds. Determining bond connectivity helps to count the bonding electrons. Thus, Sn shares its two electrons in bond formation with Cl atoms.
  • Now it’s time to decide the octet rule is satisfied in this molecule or not. In SnCl2, octet rule is not satisfied.

SnCl2 Lewis Structure Shape

Shape of any molecule can be determined from the hybridization of it. Besides that, lone pair bond pair repulsion plays an significant role in structure determination of any molecule.

The magnitude in increasing order of repulsion is-

Bond pair-bond pair repulsion < Lone pair- bond pair repulsion < Lone pair – lone pair repulsion

Due to presence of the above repulsive factor any molecule is deviated from its actual geometry.

In SnCl2 Sn has one lone pair. Thus, lone pair-bond pair repulsion is involved here but not lone pair-lone pair repulsion because Sn has only one pair of lone pair. The bonding electrons of Sn-Cl bond face the repulsion with the lone pair of Sn and also the bonding electrons of another Sn-Cl bond. As lone pair-bond pair repulsion predominates the bond pair- bond pair repulsion, the bond angle between two Sn-Cl bond decreases than the ideal case and it is shown less than 1200.

From the above parameter, we can conclude that the shape of SnCl2 is angular (v-shaped).

SnCl2 Shape
Shape of SnCl2

SnCl2 Lewis Structure Formal Charges

Formal charge is nothing but the outcome of lewis structure. Formal charge helps to identify the charge of any molecule. The following formula was introduced in chemistry to calculate the formal charge of each of the atom present in the molecule.

  • Formal charge = Total number of valance electrons – number of electrons remain as nonbonded – (number of electrons involved in bond formation/2)
  • Formal charge of Sn = 4 – 2 – (4/2) = 0
  • Formal charge of each of the chlorine atom = 7 – 6 – (2/2) = 0

SnCl2 Lewis Structure Lone Pairs

Lone pairs are those valance electrons who do not involve in bond formation. Bonding electrons are also valance electrons but they are involved in bond formation.

  • Lone pair or nonbonded electron = Total number of valance electron – number of bonded electrons.
  • Nonbonding electrons of Sn = 4 – 2 = 2
  • Nonbonding electrons of each of the chlorine = 7 – 1 = 6

Valance shell electron configuration of Sn and Cl is 5s2 5p2 and 3s2 3p5 respectively. Sn uses its two 5p electrons and Cl uses its one 3p electrons in covalent bond formation with each other.

 SnCl2 Hybridization

Hybridization is the concept of mixing atomic orbitals having comparable size and energy. After mixing, new hybrid orbitals are formed.

 VSEPR theory (valance shell electron pair repulsion theory) helps to determine the hybridization of the central atom of any molecule.

SnCl2 hybridization
Hybridization of SnCl2

Sn has total four valance electrons. Among them, two electrons from 5p orbital are involved in bond formation with two chlorine atoms and rest of the two electrons remain as nonbonded or lone pairs. These two nonbonding electrons are in 5s orbital.

For each of the chlorine atom, only one electron from 3p orbital participate to from covalent bond with Sn.

Thus, from the above image and explanation it is clear that Sn is sp2 hybridized in SnCl2. The ideal bond angle of sp2 hybridization should be 1200. But due to the repulsion present in SnCl4, the ideal bond angle is deviated and show little bit lesser bond angle (950) than the ideal case.

SnCl2 Lewis Structure Octet Rule

Octet rule states that any atom should have such number of electrons in their outer most shell or valance shell that they can attain the nearest noble gas configuration. To achieve this stable electron configuration, atoms form covalent or ionic bonds with other molecules.

This noble gas like electron configuration has some extra stability factor.

In SnCl2, octet rule is not satisfied. Sn has four valance electron and after bond formation with two chlorine, two more electron is added to its valance shell. Thus, total electrons in valance shell become six (each bonds have two and two nonbonding electrons). But chlorine atoms obey octet rule. Each chlorine atom has seven valance electrons in their outer most shell and between these seven electrons, one electron is shared with Sn. Thus, the total number of electrons in valance shell of chlorine become 8 which resembles nearest noble gas electron Ar (3s2 3p6).

SnCl2 Polar or Nonpolar

Polarity of any molecule depends upon the orientation of its substituent atoms. In SnCl2, both the Sn-Cl bonds are angular with each other. Thus, the dipole moment of one Sn-Cl bond cannot be cancelled by each other and a permanent dipole moment is observed in this molecule.

If the bond angle between two Sn-Cl bond is 1800, then the dipole moment of each of the bond will be cancelled out and the net dipole moment will be zero. But due to the orientation of two bonds SnCl2 is a polar molecule having a permanent dipole moment.

SnCl2 polarity
SnCl2, a polar molecule

Frequently Asked Questions (FAQ)

Does SnCl2 dissolve in water?

Answer: Stannous chloride (SnCl2) dissolves in water and form insoluble basic salt. SnCl2 (aq) + H2O (l) = Sn(OH)Cl (s) + HCl (aq).

What are the uses of SnCl2?

Answer: It is uses as the reducing agent in acidic solution and electrolytic baths for the purpose of tin plating.

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