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December 22, 2022·6 min·1276 words·Garland Abelman
Is H2S Ionic or Covalent? H2S is a covalent compound because, according to Fajan’s Rules, the large size and greater charge on the sulfide anion (S2-) favor the formation of a covalent bond. The small electronegativity difference between the sulfur and hydrogen atoms also contributes to the formation of a covalent bond.H2S consists of two elements, Hydrogen, and Sulfur. Hence, it is a binary compound. Industrially, pure H2S is obtained by separating it from other constituent gases of natural gas.At first glance, H2S may seem to be a very simple molecule. But, this humble compound is known to show superconductivity, i.e., zero resistance to electric current at very low temperatures (< 150 Kelvin) and very high pressures (> 100 GPa).In this article, we carry out a detailed chemical analysis to determine if H2S is Ionic or covalent.
How is a Covalent bond different from an Ionic bond?
A Covalent bond is formed when two atoms share electrons to achieve a stable electronic configuration.In the case of Ionic bonding, the two atoms in question gain and lose electrons to form a negatively charged anion and a positively charged cation, respectively.The cation and the anion gain stability for having a complete octet, and the attraction between the cation and the anion further increases the molecule’s stability.The difference between the two can be further explained by comparing the properties of their compounds.
Conditions for formation of Covalent Bond
- Both atoms should have high ionization potential as ionization potential is proportional to the energy required for ion formation.
- Both atoms should have high electron affinity to assist in sharing electrons.
- The electronegativity difference should be as small as possible because a higher contrast in electronegativity implies more ionic character and less sharing of electrons.
Polarization and Fajan’s Rules
In reality, no chemical bond is 100% ionic, nor is it 100% covalent. The percentage covalent character in a chemical bond is governed by the degree of polarization.Polarization is defined as the tendency of a cation to distort the electron cloud of an anion and vice versa.The covalent character in a chemical bond is proportional to the degree of polarization.Smaller cations induce a high degree of polarization with a large positive charge and larger anions with a large negative charge.
Why is H2S Covalent?
Let us look at the electron configuration of H and S and determine the type of bonding.Electron Configuration of H (Atomic Number 1): 1s1Electron Configuration of S (Atomic Number 16): [Ne] 3s2 3p4H is one electron short of achieving the inert electron configuration of Helium (Atomic Number 2), and S is two electrons short of achieving the inert electron configuration of Argon (Atomic Number 18).
On Pauling’s Scale of electronegativity, Hydrogen and Sulfur are assigned values of 2.20 and 2.58, respectively. A higher value indicated a more electronegative atom, and a lower value indicates a more electropositive atom.Let us consider the formation of two H+ cations and one sulfide anion S2-.Both ions are stable as far as electron configuration is concerned. However, notice that the H+ cation is very small (a free proton) while the S2- is a large (170 pm) anion. According to Fajan’s Rules, covalent bonds must be formed between the three atoms.A Lewis structure of H2S must be drawn to visualize the sharing of electrons via covalent bonding.
Bonding in H2S using Lewis structure and VSEPR Theory
We employ the following procedure to determine the structure of H2S:Step 1: Determine the central atom. In our case, we choose S as the central atom.Step 2: Count the total number of valence electrons in the molecule.n1 = 6 (from S) + 2 x 1 (from H) = 8Step 3: Count the number of electrons needed to fulfill the octet of all atoms.n2 = 8 x (number of non-H atoms) + 2 x (number of H atoms) = 8 x 1 + 2 x 2 = 12Step 4: Number of bond pairs = (n2 – n1)/2 = 4/2 = 2Step 5: Count the number of non-bonding electrons.n3 = n1 – (n2 – n1) = 8 – (12 – 8) = 4Step 6: Number of lone pairs = n3/2 = 4/2 = 2Now, we are ready to draw the Lewis structure of H2S.First, we place S at the center and place two bond pairs connecting it to the H atoms. The two bond pairs form the covalent bonds connection S to H.Note that the H atoms have achieved the electronic configuration of Ne, but the S atom is still four electrons short.To remedy this, we place the two lone pairs on the S atom. Now, the S atom has achieved the stable, inert electron configuration of Ar.
Step 7: Calculate the Formal Charge on all atoms.We can check the validity of our Lewis structure by using the concept of formal charge. Formal charge on an atom is defined as follows:Formal Charge = Valence Electrons – (0.5 x Bonding Electrons) – Non-Bonding ElectronsThe number of bonding and non-bonding electrons can be found from the Lewis structure.Formal Charge the S atom = 6 – (0.5 x 4) – 4 = 6 – 6 = 0Formal Charge for each H atom = 1 – (0.5 x 2) – 0 = 1 – 1 = 0Total Charge on the molecule = Sum of formal charges on atoms = 0 + 0 + 0 = 0This is consistent as H2S is indeed an uncharged neutral molecule. Thus, our Lewis structure is correct.After knowing the electron distribution in the molecule, VSEPR theory can be used to determine the molecule’s geometry.The repulsion between the lone pairs on the S atom and the bond pairs of the H atoms will force the molecule to adopt bent geometry.
Properties of H2S
Chemical Properties
- The gas is toxic by inhalation.
- In a polar aprotic solvent, H2S is a better nucleophile than H2O because of S being less electronegative than O.
- It slowly decomposes in the air to form elemental Sulfur.
- H2S is slightly soluble in water because of hydrogen bonding and weak acidity.
- It reacts with metals ions to form metal sulfides.
Physical Properties
- H2S is a colorless gas with a strong odor of rotten eggs.
- A very low melting point (-82° Celsius or -116° Fahrenheit) and a very low boiling point (-60° Celsius or -76° Fahrenheit) indicate the tendency of H2S to remain in the gaseous phase.
- It is a flammable gas.
- It is slightly denser than air.
- H2S can be liquified by confining it under its own vapor pressure.
Uses of H2S
- H2S is used in the qualitative analysis of inorganic compounds. Its presence often indicates the presence of sulfide anions. Bubbling the gas through the compound solution can result in the precipitation of heavy metal ions such as Pb(II), Cu(II), and Hg(II).
- In metallurgy, H2S is bubbled through to precipitate the valuable metal as metal sulfides.
- The nucleophilicity of H2S is exploited to synthesize organosulfur compounds like methanethiol, ethanethiol, and thioglycolic acid.
- H2S is used to manufacture sulfur alkali metal compounds, which in turn are used extensively in the paper industry.
Conclusion
H2S is a covalent compound as electrons are shared between the S and H atoms. The sharing of electrons results in an inert electron configuration for all the atoms.Two bond pairs of electrons are responsible for the formation of 2 single bonds between the S and H atoms. The rest of the valence electrons manifest themselves as non-bonding electrons or lone pairs on the S atom.
FAQs
Is H2S covalent or ionic? ›
The bonds of H2S are covalent because hydrogen has electronegativity about 2.2, and sulfur 2.56.
Is HS ionic or covalent? ›The type of bonds based on electronegativity is summarized above. The electronegativity value of H is 2.1 and that of S is 2.5. The electronegativity difference, which is 0.4, suggests that H-S bonds in hydrogen sulfide are polar covalent.
Can H2S form ionic bonds? ›Both H atoms remain covalently bonded to the S atom by two single bonds, as shown below: Hence, H2S H 2 S is a covalent...
Is sulfide ionic or covalent? ›Inorganic sulfides are ionic compounds containing the negatively charged sulfide ion, S2−; these compounds may be regarded as salts of the very weak acid hydrogen sulfide. Organic sulfides are compounds in which a sulfur atom is covalently bonded to two organic groups.
What type of compound is H2S? ›Hydrogen sulfide is a chemical compound with the formula H2S. It is a colorless chalcogen-hydride gas, and is poisonous, corrosive, and flammable, with trace amounts in ambient atmosphere having a characteristic foul odor of rotten eggs.
Is H2S covalent or polar covalent? ›Because hydrogen has an electronegativity of around 2.2 and sulfur has an electronegativity of 2.56, H2S bonds are covalent.
How do you know if its ionic or covalent? ›As a general rule of thumb, compounds that involve a metal binding with either a non-metal or a semi-metal will display ionic bonding. Compounds that are composed of only non-metals or semi-metals with non-metals will display covalent bonding and will be classified as molecular compounds.
Is it covalent or ionic? ›Ionic compounds are (usually) formed when a metal reacts with a nonmetal (or a polyatomic ion). Covalent compounds are formed when two nonmetals react with each other. Since hydrogen is a nonmetal, binary compounds containing hydrogen are also usually covalent compounds.
How can you tell if a bond is ionic or covalent? ›One way to predict the type of bond that forms between two elements is to compare the electronegativities of the elements. In general, large differences in electronegativity result in ionic bonds, while smaller differences result in covalent bonds.
How many covalent bonds does H2S have? ›Therefore, it share 2 electron with two hydrogen atom and forms 2 covalent bond with it.
How the bond is formed in H2S? ›
In the H2S molecule, two Hydrogen atoms form a bond with the central Sulfur atom. Two single bonds are formed in the molecule. These bonds take up four valence electrons, and hence there are four other valence electrons left.
What is the covalent name of H2S? ›Then, we have to write the name of second non-metal that is sulfur with a suffix -ide. Thus, the name of the covalent compound H2S H 2 S is hydrogen sulfide.
Is H2S polar or nonpolar or ionic? ›Hydrogen sulfide is non-polar on account of its nonpolar H–S bonds. The EN difference between hydrogen and sulfur is 0.4, so hydrogen and sulfur form non-polar bonds. Although it has an asymmetrical molecular geometry, the entire molecule is non-polar dues to the absence of any polar bonds.
What is the covalent compound of H2S? ›Explanation: Hydrogen sulfide (or sulphide) is a covalent compound with the chemical formula H2S . Each molecule of hydrogen sulfide contains a central sulfur atom bonded to two hydrogen atoms.
Is H2S an example of hydrogen bonding? ›For example, consider hydrogen sulfide, H2S, a molecule that has the same shape as water but does not contain hydrogen bonds. Due to its relatively weak intermolecular forces, H2S boils at about −60 °C and so is a gas at room temperature.
Is H2S a covalent hydrides? ›H2S is a covalent hydride because it contains 2 covalent bonds between S and H.
Is H2S a double covalent bond? ›Sulfur shares 2 valence electrons through 2 single covalent bonds to 2 terminal hydrogen atoms. Each hydrogen atom shares its only electron.
Is HS a polar covalent bond? ›Answer and Explanation: The H-S bond is nonpolar. The electron negativity difference between the two atoms decides the polarity of a covalent bond in a molecule. If the electronegativity difference is greater than 0.4, the bond between the two atoms is polar.
What are examples of ionic and covalent bonds? ›- Why is metallic bonding different from ionic or covalent bonding? ...
- Give two example in each case : ...
- Which one of the following compound contains both ionic and covalent bond?
If the electronegativity difference between the metal and nonmetal is greater than 1.7, the bond is ionic.
Which of the following is ionic and covalent? ›
Thus, NaOH has covalent and ionic bond.
What is an example of ionic bond? ›One example of an ionic bond is the formation of sodium fluoride, NaF, from a sodium atom and a fluorine atom. In this reaction, the sodium atom loses its single valence electron to the fluorine atom, which has just enough space to accept it.
What is an example of covalent bond? ›Five examples of covalent bonds are hydrogen (H₂), oxygen (O₂), nitrogen (N₂), water (H₂O), and methane(CH₄). 2. What is a covalent bond? A chemical bond involving the sharing of electron pairs between atoms is known as a covalent bond.
Does h2 have one covalent bond? ›...
Covalent Bonds.
| Atom | Valence |
|---|---|
| Hydrogen | 1 |
| Fluorine | 1 |
| Bromine | 1 |
| Chlorine | 1 |
Covalent molecules made of only one type of atom, like hydrogen gas (H2), are nonpolar because the hydrogen atoms share their electrons equally.
Is H2S polar or nonpolar quizlet? ›Terms in this set (10)
The compound H2S contains polar bonds but the molecule is nonpolar.
H2S is a slightly polar molecule because of the small difference in electronegativity values of Hydrogen (2.2) and Sulfur (2.58) atoms.
Is HS polar or nonpolar covalent? ›The H-S bond is nonpolar. The electron negativity difference between the two atoms decides the polarity of a covalent bond in a molecule. If the electronegativity difference is greater than 0.4, the bond between the two atoms is polar. The electronegativity of sulfur and hydrogen are 2.5 and 2.1, respectively.
What ion is HS? ›Bisulfide (or bisulphide in British English) is an inorganic anion with the chemical formula HS− (also written as SH−).
Which compound is HS? ›| PubChem CID | 5047209 |
|---|---|
| Molecular Formula | HS- |
| Synonyms | sulfanide hydrosulfide HS anion 15035-72-0 bisulfide More... |
| Molecular Weight | 33.08 |
| Dates | Modify 2023-02-25 Create 2004-09-16 |
What type of bond is found in the HS bond? ›
A symmetric hydrogen bond is a special type of hydrogen bond in which the proton is spaced exactly halfway between two identical atoms. The strength of the bond to each of those atoms is equal. It is an example of a three-center four-electron bond. This type of bond is much stronger than a "normal" hydrogen bond.
Is H2 an example of polar covalent bond? ›Covalent molecules made of only one type of atom, like hydrogen gas (H2), are nonpolar because the hydrogen atoms share their electrons equally.
Is the HS bond in H2S nonpolar? ›H2S is a weakly polar molecule. H2S is made up of two H-S bonds. Due to a very small difference in electronegativity between the bonded atoms, an individual H-S bond is considered non-polar. The asymmetric, bent shape of H2S due to two lone pairs of electrons present on central sulfur makes the overall molecule polar.
What is the name of h2s? ›Hydrogen sulfide is a colorless, flammable, extremely hazardous gas with a “rot- ten egg” smell. Some common names for the gas include sewer gas, stink damp, swamp gas and manure gas. It occurs naturally in crude petroleum, natural gas, and hot springs.
Is h2s a strong acid? ›∴H2S is a weak dibasic acid.
How does H2S form? ›It is produced when bacteria break down plant and animal material, often in stagnant waters with low oxygen content such as bogs and swamps. Volcanoes, hot springs and underwater thermal vents also release hydrogen sulfide.
What is the property of H2S? ›Physical Properties of Hydrogen Sulphide
Hydrogen sulfide is slightly denser or heavier than air but fairly soluble in water. Hydrogen sulphide is a colourless, poisonous gas that can lead to headaches even if it is inhaled in small quantities. It has a distinct rotten egg smell. Hydrogen sulfide is a flammable gas.
- Look at the chemical formula.
- Identify the elements in the compound.
- Determine if the elements are metals or nonmetals (using a periodic table)
- Metal – Metal = Metallic.
- Metal – Nonmetal = Ionic.
- Nonmetal -- Nonmetal = Covalent.
Historical Background. Hydrogen bonds (1, 2) are one of the principal intermolecular forces. A special class are ionic hydrogen bonds (IHBs) that form between ions and molecules with bonds strengths of 5−35 kcal/mol, up to a third of the strength of covalent bonds.
Which of the following does not contain covalent bonds? ›So CoCl2 is an ionic compound and doesn't have covalent bonds.