【】H2O Lewis Structure ,Valence Electrons ,Formal Charge,Polar or Nonpolar

H2O Lewis Structure 

Answer:

H2O Lewis structure(water electron dot structure) is that type of diagram where we show the total eight  valence electrons of H2O as dots , or dots and dashes(-).In Lewis structure,it is common that a bonding pair of two electrons can be shown by  dash(-) or dots(●●) but a lone pair of two electrons is shown by dots[●●].

H2O Lewis Structure

Or,

Water Lewis Structure

In H2O Lewis structure,there are two single bonds that are going from the oxygen atom to hydrogen atoms.Besides,there are two lone pairs around the oxygen atom.

In H2O Lewis structure,the oxygen atom follows the octet rule and the hydrogen atoms  follow the duet rule.

In H2O Lewis structure,we get four pairs of electrons.Out of four pairs of electrons,H2O has two bond pairs and two lone pairs of electrons.

Explanation:

Hello,today I am going to draw the H2O Lewis  structure  in just four steps.


H2O Lewis  structure Setup  Step-1:

To draw the H2O Lewis   structure , we have to find out the H2O valence electrons first.We express valence electrons as dots in lewis dot structure.

To get the valence electrons of oxygen,we need to look at the electronic configuration of oxygen.



O(8)=1s²2s²2p⁴



The highest value of principal quantum number  here is n=2.


The highest value of principal quantum number ,n , indicates the valence shell and we know the electrons in valence shell is called valence shell.




The nunber of valence electrons in oxygen is 6.

Again, we have to find out the valence electrons of hydrogen,H.

To get the valence electrons of hydrogen,we need to look at the electronic configuration of hydrogen.


H(1)=1s¹

The highest value of principal quantum number here is n=1.

The highest value of principal quantum number ,n , indicates the valence shell and we know the electrons in valence shell is called valence shell.




The nunber of valence electrons in hydrogen is 1.

    Step-2:H2O Valence

 Electrons  

Now we have to count total number of valence electrons for H₂O.


O =6

2×H=1×2=2

So,the total number of  H₂O valence electrons is eight( 6+2=8 ).

              H2O Lewis  structure Setup  Step-3:

Now we have to determine the central atom in H₂O.The central atom is that kind of atom that is single or that has lower electronegativity.In case of H₂O,O is the central atom and H is the outer atom.Remember that hydrogen is always the outer atom.




              H2O Lewis  structure Setup  Step-4:

Now we need to connect the outer atoms with  the central atoms using dots s or line(-).Every line represent two 【●●】dots or two valence electrons.

Or,

In the above structure,we have used 4 valence electrons out of eight.So,we have 8-4=4 left.


Now we will use these 4 valence electrons to satisfy the octet  for central atom.

Or,

The above structure is the Lewis structure for H₂O.

H2O Formal Charge

Now we can calculate formal charge of each atoms in H2O Lewis structure by applying the formula for formal charge.

Rule-1:

Rule-2:

Formula-3:

Formal Charge=Valence Electrons-Dots-Lines

O--->6-4-2 =0

H-->1-0-1=0

Rule-4:

Formal Charge =Valence Electrons - unshared Electrons - 1/2 (Shared Electrons)

How do you calculate the formal charge of oxygen in water?

●The formal charge of O (oxygen) in H2O is zero.

•Valence electrons of O =6

•Shared electrons of O= 4

•Unshared electrons of O = 4

●F.C. of O  =6- 4 -1/2(4)

                  =6-4-2

                 =6-6

                   =0 

●What is the formal charge of H  in H2O?

●The formal charges of H (hydrogens) in H2O are also zero.

•Valence electrons of H =1

•Shared electrons of H= 2

•Unshared electrons of H =O

F.C. of H = 1 - 0 -1/2(2)

                  =1-0-1

                 =1- 1

                   =0 

Formal charge of oxygen and hydrogen in H2O

●What are the formal charges on H and O in a water molecule?

Answer:

The formal charges on H and O in a water molecule is zero.

So,the best H2O Lewis dot structure  will be the one where most atoms will have zero formal charge.Here is the best Lewis dot structure for H2O(water).

Best H2O Lewis Structure

Continue

Some Questions and Answers

●How many valence electrons does H2O have?

Answer:

H2O has eight valence electrons.Two valence electrons from two hydrogen atoms and six valence electrons from one oxygen atom.Thus,the number of  valence electrons of H2O is  eight.

●What is total number of electrons in Lewis structure of water molecule?

 Answer:

Eight is total number of electrons in Lewis structure of water molecule.

Is H2O polar or nonpolar?

Answer:

H2O is a polar molecule.Again,water is polar molecule because of its bent shape(V type shape) or  geometry which makes the net molecular dipole moment non zero.Again,Since H2O has net molecular dipole moment,H2O is polar.

Explanation:

Here are the few steps that you help you to determine that water,H2O, is a polar molecule.

           Step-1:

Draw the Lewis structure of H2O.

Is H2O polar or nonpolar

             Step-2:

After drawing Lewis structure of H2O,now you need to consider the electronegativity difference between atoms.

Here oxygen is more electronegative than hydrogen.So,every  oxygen-hydrogen bond is polar.

               Step-3:

Now consider bond dipole moment.

As both oxygen and hydrogen bonds are polar,every bond has a dipole moment.

             Step-4:

Now consider the geometry or shape of H2O molecule by applying VSEPR theory.

According to VSEPR theory,we get bent shape or geometry of H2O.

                 Step-5:

Now consider the net molecular dipole moment.

As the shape of H2O is bent(V type),one bond dipole moment does not  cancel another bond's dipole moment.Thus,we get non zero value for the net molecular dipole moment .As the value of net molecular dipole moment is not zero,we can say that H2O is polar.