Nitric Acid Lewis Structure: Drawing And Detailed Explanations

In this article, “nitric acid lewis structure”, Lewis structure drawing procedure, few properties with some detailed explanations are discussed briefly.

Nitric acid is basically an ionic compound consisting with H+ and NO3 ion. Nitrogen and oxygen have 7 and 8 electrons respectively. Among these, only valance electrons are shown around the respective atoms and rest of the electrons participate in covalent bond formation.

Main outlook of this article is to draw and analyse the lewis dot structure of nitric acid shown below.

What is Lewis Structure?

Lewis structure or known as lewis dot structure is one type of representation of any molecule with the valance shell electrons around the respective species and the bonds attached with the atoms.

Lewis dot structure was first named from the name of eminent scientist Gilbert. N. Lewis. He first introduced this lewis structure concept in his article named as “The Atom and The Molecule” in the year of 1916.

Lewis structure is actually helps to determine the structure, number of electrons participating in covalent bond or formation as well as the electrons remain as nonbonded pairs. These all are shown in lewis structure. It also gives a way out to calculate the formal charge of each of the atoms in a particular molecular species.

Process of Drawing Lewis Structure

There are some points must be followed to draw the lewis structure which are explained below-

  • Atomic numbers as well as number of valance electrons of each and every species will be calculated first.
  • Number of electrons to fill up the octet or the electrons needed to fill up the valance shell of that species counted for each atom to draw the lewis structure.
  • The number of covalent or ionic bonds present in that molecule should also be determined.
  • After determining the above parameters, skeletal structures of the molecule will be drawn showing the valance shell electrons and the bonds present in the molecule.
nitric acid lewis structure
Lewis dot structure of carbon dioxide. Image Credit: Wikimedia Commons.

In this above lewis structure of carbon dioxide, the nonbonded electrons of oxygen are shown around the oxygen atoms. It has total eight electrons and the electron configuration is 1s2 2s2 2p4. Total valance electron is six. Among these six electrons, two electrons participate in covalent bond formation with carbon. Rest of the four electrons are shown as nonbonded electrons around each of the two oxygen atoms.

Carbon has atomic number six with electron configuration 1s2 2s2 2p2. Thus, it has four outer most shell electrons and all the valance electrons are used to form the four covalent bonds with two oxygen atoms. So, no electrons are shown around carbon atoms.

Nitric Acid Lewis Structure

Nitric acid, known as aqua fortis (English meaning strong water) is a very strong inorganic acid having molar mass 63.012 g/mol and density 1.41 g/cm3. The lewis structure of nitric acid can also be drawn by using the methods explained above.

HNO3 Lewis structure
Nitric Acid Lewis Structure.

Nitric acid contains three types of atoms, hydrogen, oxygen and nitrogen. Oxygen and nitrogen have eight and six electrons respectively. Oxygen has total six electrons in its outer most shell and nitrogen has five electrons in its outer most shell.  

Oxygen atoms are denoted as 1,2,3 respectively. Among these electrons, number 1 oxygen denoted its four electrons (among 8 valance electrons) in covalent bond formation with nitrogen and hydrogen.  Similar case is observed for number 3 denoted oxygen also. But different scenario is for number 2 denoted oxygen. In this oxygen, six electrons are shown as nonbonded around the oxygen atoms and becomes negative.

Nitrogen has five electrons in its valance shell and it uses its four out of these five outer most shell electrons in bond formation with three oxygen atoms and becomes +1.

Formal Charge Calculation of Nitric Acid

Formal charge of each of the atom in a whole molecular species can be calculated using the following formula-

  • Formal charge = Total number of valance electrons – number of electrons remain as nonbonded – (number of electrons involved in bond formation/2)
  • Formal charge on Number 1 and number 3 denoted oxygen = 6 – 4 – (4/2) = 0
  • Formal charge of number 2 denoted oxygen = 6 – 6 – (2/2) = -1
  • Formal charge on nitrogen = 5 – 0 – (8/2) = +1
  • Formal charge on hydrogen = 1 – 0 – (2/2) = 0
File:Nitric acid.svg
Nitric Acid.
Image Credit: Wikimedia Commons

Frequently Asked Questions (FAQ)

Does nitric acid react with water?

Answer:  Nitric acid decomposes into water it is decomposed into nitrogen dioxide (NO2), oxygen (O2) and resultant solution becomes yellowish colour.

HNO3 = NO2 + O2 + H2O

Does nitric acid react with metal?

Answer: Nitric acid reacts with metal and liberate hydrogen gas (H2). After reacting with nitric acid magnesium (Mg)  forms magnesium nitrate [Mg(NO3)2] and hydrogen gas.

Mg + HNO3 = Mg(NO3)2 + H2

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