NOCl Lewis Structure & Characteristics: 17 Complete Facts

NOCl, a component of aqua regia, is a yellow-coloured compound with high oxidizing power. Let us discuss the structure and some important characteristics of NOCl in detail.

The structure of NOCl is bent shaped having bond angle 1130 with the hybridization of central atom sp2. Nitrogen is attached with oxygen through a double bond and chlorine through a single covalent bond in this compound. It is a polar compound which is dissolved in water.

Let us explain the lewis structure, hybridization, bond angle, valence electrons of nitrosyl chloride briefly.

How to draw NOCl lewis structure?

Lewis structure is a structural representation of any molecule. In which the bonding as well as nonbonding electrons are shown clearly with below steps.

Determining of valence electron:

The constituent atoms of NOCl nitrogen, oxygen and chlorine have five, six and seven electrons in their respective valence shell.

Finding out the bonding electrons: 

Total three covalent bonds (one pi and two sigma) are present in NOCl lewis structure. Therefore, (3×2) = 6 electrons are involved in bonding.

Finding out the nonbonding electrons:

The atoms of NOCl, nitrogen, oxygen and chlorine have two, four and six nonbonding electrons respectively which are shown as electron dot in NOCl lewis structure.

NOCl Lewis Structure

NOCl Lewis Structure Resonance

Resonance, also known as mesomerism, is one way of describing the delocalization of electron cloud from one atom to another atom. Let us give an overview on it.

Total two resonance lewis structures can be drawn for NOCl. Between these two structures, one is more stable than the other. Therefore, the contribution of the two resonance structures is not equal towards its hybrid mesomeric structure.

Nitrogen has double bond with oxygen in greater contributing structure and chlorine forms double bond with nitrogen in the lesser contributing structure. The contribution of latter one is lesser because it contains positive and negative charge in the NOCl structure.

NOCl Resonance Structure

NOCl Lewis Structure Shape

Lewis structure shape of any molecule can be determined by the three-dimensional arrangement of the atoms as well as the bonds connecting the atoms. Let us explain it.

The lewis structure shape of NOCl is angular or bent shaped with an asymmetric charge distribution on the central atom, nitrogen. But the geometry of NOCl is trigonal planar as it is a sp2 hybridized molecule.

The difference between molecular shape and geometry is observed due to the lone pair of central atom because this lone pair faces lone pair-bond pair repulsion from the N-O and N-Cl bond. If there is no lone pair on nitrogen then it shows its actual geometrical structure, trigonal planar.

Shape of NOCl

NOCl Lewis Structure Formal Charge

Formal charge is the individual charge carried by the constituent atoms in a molecule. Let us talk about this.

The formal charge calculation of NOCl is = {Total number of valance electrons – number of electrons remain as nonbonded – (number of electrons involved in bond formation/2)}. It is calculated for the most stable lewis structure.

  • Formal charge of the nitrogen atom = 5 – 2 – (6/2) = 0
  • Formal charge of the oxygen atom = 6 – 4 – (4/2) = 0
  • Formal charge of the chlorine atom = 7 – 6 – (2/2) = 0
  • Therefore, the total formal charge of NOCl is zero.

NOCl Lewis Structure Angle

Lewis structure angle is denoted the angle connecting two covalent bonds and one atom. Let us discuss it in detail.

The angle lewis structure of NOCl is 1130. Molecular bond angle can be determined from hybridization of the central atom which is sp2 in NOCl. The bond angle of a sp2 hybridized molecule should be 1200. But due to repulsion bond angle of NOCl is decreased from its ideal bond angle.

The lone pair of nitrogen is involved with the lone pair-bond pair repulsion of N-O and N-Cl bond. This repulsion decreases the bond angle of NOCl from 1200 and the actual bond angle becomes 1130.

 NOCl Lewis Structure Octet Rule

Octet rule is a rule of inorganic chemistry which depicts that atoms like to have eight electrons in their valence shell like their nearest noble gas. Let us explore this.

All the atoms in NOCl satisfies lewis structure octet rule in the following way-

  • Nitrogen contains five valence shell electrons and in NOCl it is attached with oxygen and chlorine atom by double bond and single bond respectively. After bonding it achieves eight electrons in its valence shell.
  • Oxygen also satisfies octet rule it also gains eight electrons after bonding with nitrogen as it already has six electrons in its outer most shell.
  • Octet rule is also satisfied in chlorine because it gets eight electrons after formation bond with nitrogen.

NOCl Lewis Structure Lone Pairs

Lone pairs are those valence electrons which are not used in bonding with other atoms in molecule. Let us discuss it.

All of the atoms Nitrogen, oxygen and chlorine, have lone pairs in NOCl lewis structure. Number of lone pairs can be determined by using the following formula- Formula of calculation of nonbonded electron = (Total number of valance electron – number of bonded electrons).

  • Number of lone pairs in nitrogen = 5 – 3 = 2 = 1 lone pair
  • Number of lone pairs in oxygen = 6 – 2 = 4 = 2 lone pairs
  • Number of lone pairs in chlorine = 7 – 1 = 6 = 3 lone pairs.
  • Therefore, total number of lone pairs = 1+2+3 = 6

NOCl Valence Electrons

Valence electrons are those which are revolving in the outer most shell of the atom. Let us give a clear discussion on it.

The valence electrons of NOCl are the summation of the total outer most shell electrons of nitrogen, oxygen and chlorine. Nitrogen, oxygen and chlorine have five, six and seven electrons in their respective valence shell. Therefore, total number of valence electrons in NOCl are = 5+6+7 = 18.

All of the participating atoms of NOCl are p-block element. They have electron configuration 2s2 2p3 for nitrogen, 2s2 2p4 for oxygen and 3s2 3p5 in their valence shell. From this electron configuration, number of valence electrons can be calculated easily.

NOCl Hybridization

Hybridization is the concept of mixing of two atomic orbitals having similar energy and similar symmetry to generate a new hybrid orbital. Let us talk about this.

The hybridization of nitrogen in NOCl is sp2. In this compound nitrogen is central atom and 2s along with 2p orbitals of it are involved in sp2 hybridization. Total three orbitals (one s orbital and two p orbitals) are participating to generate the new sp2 hybrid orbital.

Molecular shape of NOCl can be predicted from this sp2 hybridization. The geometrical shape should be trigonal planar. But due to involvement of lone pair-bond pair repulsion, NOCl becomes angular rather than trigonal planar.

Is NOCl a solid?

Solid, liquid or gas is the physical state of any compound, which can be decided from its boiling point. Let us explore it.

NOCl is not a solid rather it is a yellow-coloured gaseous compound. The boiling point of nitrosyl chloride is -5.550C.

Why and how NOCl is not a solid?

NOCl is a gas, not a solid because it is formed between the reaction of gaseous compounds like nitrous gases (NO and NO2) with elemental chlorine (Cl2) or hydrogen chloride gases (HCl). Besides that, the boiling point of NOCl is very low. Therefore, it is present as a gas in ambient temperature.

Is NOCl soluble in water?

Solubility in a particular solvent depends upon the nature of both the solute and solvent. Let us give an explanation on it.

NOCl is definitely soluble in water and it also reacts with water to produce nitric acid (HNO3), nitric oxide (NO) and HCl gas. The reaction denotes- NOCl + H2O = HNO3 + NO +HCl.

Why NOCl is soluble in water?

NOCl is soluble in water as it is a highly polar molecule and water is also a polar solvent. The polar solute is attracted by the water through hydrogen bonding.

How NOCl is soluble in water?

The NOCl molecules get dissolved in water as the water molecules are associated with strong intramolecular hydrogen bonding and the NOCl molecules compete with the hydrogen bonding present in the water molecule. These hydrogen bonding will be broken and NOCl becomes soluble in water.

Is NOCl polar or nonpolar?

A polar molecule contains separation of two opposite charge, positive and negative in it which is absent in a nonpolar molecule. Let us talk about this.

NOCl is a polar molecule with an overall dipole moment 1.9 D. Orientation of the two bonds, N-O and N-Cl and the electronegativity difference between N, Cl and O makes it a polar molecule.

Why and how NOCl is a polar molecule?

NOCl is polar because the bond dipole moment of two bonds N-O and N-Cl is not cancelled by each other. This bond moment cancellation is not occurred due to angular shape of NOCl. Besides that, the N-O and N-Cl bonds are sufficiently polar because of the electronegativity difference between the atoms.

Is NOCl an acid or base?

Acidity or basicity depends upon the capability of donating proton or accepting protons. Let us explain it.

NOCl is a Bronsted-Lowry acid as it can donate proton to any electron rich species or Bronsted-Lowry bse which are ready to accept it.

Why and How NOCl is acidic in nature?

NOCl is acidic because it is formed due to the combination of hydrochloric and nitric acid. The reaction denotes – HNO3 + HCl = 2[Cl] + 2H2O + NOCl. Nitrogen in NOCl is gets partially positive charged which can react with any species having larger electron density like an alkene.

Is NOCl an electrolyte?

Electrolyte are those which can be dissociated into two oppositely charged ions. Let us discuss it.

NOCl is not an electrolyte because in aqueous solution it cannot be dissociated into ions, rather it reacts with water.

Why and how NOCl is not an electrolyte?

NOCl is not an electrolyte as the there is no atom which can be positively charged after dissociation of NOCl because all the atoms are basically electronegative according to pauling scale. Therefore, no positively or negatively charged species can be produced from NOCl after dissolving in water.

Is NOCl ionic or covalent?

Covalency or ionic character is defined by the sharing or completely transferring of electron pairs respectively. Let us discuss about it.

NOCl is a covalent compound as nitrogen as attached through double covalent bond and single covalent bond with oxygen and nitrogen respectively.

Why and how NOCl is a covalent compound?

NOCl is covalent compound because all the participating atoms of NOCl is nonmetal and ionic compound must have minimum one metal. Besides that, the bonds between the nitrogen, oxygen and chlorine, are formed due to sharing of electron pairs depending on the electronegativity difference of them.


Nitrosyl chloride is a water-soluble covalent compound having bent shaped with bond angle 1130. It has different uses in different fields like as catalyst, oxidizing agent, bleaching agent for flour and synthetic detergents.

Aditi Roy

Hello, I am Aditi Ray, a chemistry SME on this platform. I have completed graduation in Chemistry from the University of Calcutta and post graduation from Techno India University with a specialization in Inorganic Chemistry. I am very happy to be a part of the Lambdageeks family and I would like to explain the subject in a simplistic way. Let's connect through LinkedIn-

Recent Posts