21 Facts On K2s Lewis Structure & Characteristics

Potassium sulphide is an inorganic compound which is rarely found. Let us discuss some facts about potassium sulphide with all its details.

Potassium sulphide(k2s) is a colourless solid which is yellow in colour when contaminated with any impurities. The molar mass of potassium sulphide is 110.262 g/mol. Its odour is like rotten egg as similar to hydrogen sulphide,H2S. Potassium sulphide’s boiling and melting point is 9120 C , 8400C respectively.

It is hygroscopic. It can cause serious hazards like skin burns, fire hazards and environmental issues too. Potassium sulphide is prepared by heating potassium sulphate with coke or reacting potassium with sulphur in presence of ammonia. Let us go through some details of potassium sulphide in the following sections.

 How To Draw K2S Lewis Structure ?

The Lewis structure of a molecule or a compound is drawn to understand how the bond formed. Let us understand how to depict the Lewis structure of potassium sulphide.

Count it’s Valence Electrons

First of all we need to get an idea about the valence electrons involved here. The valence electrons present in potassium and sulphur is 1 ,6 respectively.

Recognise it’s bond formation

We know that potassium being a metal always donates it’s electrons and sulphur being a non- metal has a tendency to accept that electrons into it.

Assign it’s Lewis Structure

So here instead of mutual sharing only one atom shares it’s electrons and the other accepts that. Hence here ionic bond forms.Two atoms of potassium shares it’s one electron to one sulphur to form an ionic bond.

k2s lewis structure
Lewis Structure of K2S

K2S Lewis Structure Octet Rule

In accordance with octet rule there should be eight electrons in the valence shell of an atom if it makes a stable bond. Let us discuss whether k2s obeys octet rule or not.

K2S Lewis structure obeys octet rule. Two atoms of Potassium donates it’s one electron to sulphur to make its octet satisfied while sulphur with six valence electrons accepts that two electrons from two Potassium atoms to get its octet fulfilled. So here both the atoms obey octet rule.

K2S Lewis Structure Resonance

Resonance is the delocalisation of electrons involved in a molecule. Let us see whether potassium sulphide undergo resonance.

K2S Lewis structure does not undergo resonance. Because it’s an ionic compound which is formed by the attraction between a positive charged cation and negative charged anion.

K2S Lewis Structure Shape

The shape of a molecule can be found out through valence shell electron pair repelsion theory. Let us determine the structure of potasssium sulphide.

The shape of K2S Lewis structure is a crystal like structure which is similar to antifluorite structure. The electronic geometry is tetrahedral. The shape of any molecule is found out in accordance with the VSEPR theory.

K2S Lewis Structure Bond Angle

Bond angle can be defined as the angle between the atoms present in a molecule. Let us look into the angle of potassium sulphide.

Potassium sulphide is a compound with bond angle is 109.50. Since it has tetrahedral electronic geometry it has this bond angle.

K2S Lewis Structure Formal Charge

The formal charge of any compound can be found through a simple formula and it is given below. Let us find out the formal charge of potassium sulphide.

The formal charge of potassium sulphide is zero and it is stable.

  • Formal charge = Valence electrons – non- bonding electrons – No. of bonds
  • Formal charge of potassium = 1-0-1 = 0
  • Formal charge of sulphur = 6-4-2 = 0

K2S Lewis Structure Valence Electrons

The electrons present in outer shell of any atom is called it’s valence electrons. Let us see how many valence electrons do potassium sulphide has.

K2S Lewis structure contains eight valence electrons.The outer electronic configuration of potassium is 4s¹ and sulphur is 3s² 3p⁴. So they have one and six electrons in the outer shell respectively. So in total eight electrons in its valence shell.

K2S Lewis Structure Lone pairs

The electrons which did not particpate in bonding is called non-bonding electrons or lone pairs. Let us see do potassium sulphide have any lone pair in them.

In potassium sulphide lone pairs are only seen in sulphur. Sulphur with six electrons get two electrons from two atoms of Potassium to form their bond. Out of six electrons in sulphur there are two lone pairs or four non- bonding electrons.

K2S Lewis Structure Hybridisation

Hybridisation is a process that is completely dealt with covalent compounds. Let us look hybridisation in potassium sulphide.

Ionic compounds cannot be explained in terms of hybridisation. So there is no hybridisation in K2S. Hybridisation can’t be used here because the ionic compounds formed by alternating  positive and negative charges will arrange themselves in a tightly packed crystal structure.

The crystal structure of potassium sulphide is antiflourite, where small potassium ions occupies the tetrahedral sites,large sulphide ions in the eight coordinate sites.

Is K2S an Acid or Base ?

The ability of a substance to furnish H+ ions is the acidic strength and ability to donate OH ions is it basic strength. Let us see potassium sulphide is acidic or not.

Potassium sulphide is a basic substance.

Why and How k2s is Basic ?

Let us know why potassium sulphide exhibits basic nature.

The acidity or basicity of any substance is found through its pH value.The pH of potassium sulphide is found to be greater than seven. So it is basic in nature.

Is K2S Soluble in Water ?

Solubility of a substance is its ability to dissolve in other liquid. Let us look about the solubility power of potassium sulphide in various solutions.

Potassium sulphide is completely soluble in water. It dissolves with water to give potassium hydrosulphide, KSH and potassium hydroxide, KOH. Instead of this potassium sulphide is soluble in ethanol, glycerol and insoluble in ether.

Why and How k2s Soluble in Water?

Let us try understand the solubility of k2s in water.

K2S dissolves with water. Potassium sulphide is a polar molecule so it can gets easily get interacted with water. Because water is also a polar molecule. Both the compounds being polar in nature can interact very easily so they will get dissolved each other.

Is K2S Ionic or Covalent ?

Covalent compounds are formed by the mutual sharing of electrons between the atoms.Let us understand potassium sulphide has covalent or ionic character.

Potassium sulphide is an ionic compound. Potassium donates it’s one electron to sulphur to form Potassium sulphide.

Why and How k2s is Ionic ?

Let us know more about the ionic character of potassium sulphide.

K2S is ionic in nature. When the metal potassium donates the electron it become positively charged while sulphur accepts this and became negatively charge. Here one atom donates and the other accepts electron. Both the opposite charged atoms get attracted to form ionic bond here.

Is K2S an Electrolyte ?

An electrolyte is a substance which get dissociated in water to  form charged ions. Let us know whether potassium sulphide is an electrolyte.

Potassium sulphide is an electrolyte which conducts electricity.

Why and How k2s is an Electrolyte?

Let us know more about the electrolytic property of k2s.

K2S is an electrolyte. It is because being a polar molecule potassium sulphide when dissolved in water dissociates into its ions and conducts electricity. So

Is K2S Polar or Non polar ?

Polarity is a phenomena which arise due to the change in the dipole moment of atoms in a molecule. Let us see potassium sulphide has polar or non-polar nature in the below description.

k2s is a polar molecule due to the difference in the values of dipole moment of both potassium and sulphur. Potassium is a alkaline metal while sulphur is a non metal.

Why and How k2s is Polar ?

Let us check due to what reasons kes is polar.

When two oppositely charged atoms are separated by some distance there arise a factor called dipole moment and such compounds will be polar. If not then they will be non- polar. In some cases having two opposite charges may be create a polar compound.

Symmetric arrangement of atoms can cancel each other the dipole moment and they will be non- polar in nature. So not only charges, the arrangement of atoms also determines whether it is polar or not.

Is K2S Aqueous ?

Aqueous means whether the substance is liquid like nature or dissolved in water. Let us discuss K2S is aqueous or non- aqueous.

Potassium sulphide is a colourless solid substance which is rarely found.

Is K2S a Salt ?

Salt is a substance that is formed as a result of reaction between acid and base. Let us know K2S is a salt or not a salt.

Potassium sulphide is a salt made with potassium cation and sulphide anion. Salt is a neutral substance with a positive and negative charged ions.

Is K2S a Strong Base ?

Base is a substance which donate OH ions when dissolved in water. Let us discuss about the strength of basicity in K2S .

Potassium sulphide is found to be basic in nature.

Why and How k2s is a Strong Base?

Let us study about the strong basicity of k2s.

k2s forms potassium hydroxide a strong base when it gets dissolved in water. Therefore when dissolved in water potassium sulphide is a strong base.

Does K2S Form a Covalent Bond ?

Covalent bonds are due to the common sharing of electrons between the atoms. Let us learn about whether K2S is covalent or not.

Potassium sulphide is an ionic compound not a covalent compound. Because it is formed by the attraction of two opposite charges.

Why and How k2s is not Covalent?

Let us see why k2s is not Covalent.

k2s is formed by the attraction between positive potassium and negative sulphide ion. So there is no chance of covalent bond formation over here.

Is K2S a Gas ?

Gas is a form of substance which has no definite shape and volume. Let us see the nature of K2S that is whether it is solid, liquid or gas.

Pottasium sulphide is a solid not a gaseous substance. Gas is a phase where there is no shape and volume. But here k2s has a definite shape.

Is K2S Dipole- Dipole ?

Dipole- Dipole interaction is an intermolecular force exist in between certain molecules. Let us look if dipole dipole interaction exist in potassium sulphide.

Dipole Dipole interaction is observed in potassium sulphide. In k2s there is a possibility for interaction between the positive potassium of one K2S with negative sulphur of other K2S. So there can be dipole- dipole interaction exists in between potassium sulphide molecules.

Since there is attraction between the dipole of one molecule to the other K2S undergo dipole dipole attraction.


Potassium sulphide is a inorganic compound which is used in pyro technique effects, analytical chemistry, medicinal fields.

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Aparna Dev

Hi... I am Aparna Dev, a chemistry Postgraduate with a good understanding of chemistry concepts. I am working in Kerala Minerals and Metals Limited Kollam with experience in the development of electrocatalysts as a part of post graduate thesis. Let's connect through LinkedIn-https://www.linkedin.com/in/aparna-dev-76a8751b9

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