Login

what are polar and non polar bonds?

and what is dipole movement of polar compounds?

The bond is said to polar if the electronegativity difference between the bonded atoms is ranging from 0.4 to 1.6

Example : Bond between Carbon and oxygen. Oxygen(electronegativity=3.5) - Carbon (electronegativity=2.5) .The difference in electronegativity is 1 and the bond is polar.

Similarly if the electronegativity difference ranging from 0.0 to 0.4 it is said to be non polar. Example: Bond between same atoms(like carbon-carbon) or like Carbon and Hydrogen(EN difference is lee than 0.4)

Dipole moment is the measure of the polarity in polar molecule.It can be calculated from product of magnitude of charge and distance between the centres of positive and  negative charge. 

Formula:Dipole moment(µ)=charge(Q)×distance of separation(r), It is usually expressed in Debye Units (D). It is a vector quantity. In case of polyatomic molecule the dipole moment is calculated by vector sum of the dipole moments of various bonds. Although a single bond may be polar but the vector sum may be Zero and this gives non polarity to the molecule. Example is BF3  

  • 0
View Full Answer

first forget all doubts you have about your doubts on polar bonds and all otherwise you will be confused.

lets consider a molecule HF.

H - F

there are shared electrons between the atoms.

but in some cases, a atom pulls electrons with more stronger energy than other atom.

this energy is called electronegetivity.

electronegetivity for Hydrogen is 2.20 for Flurine is 3.98. ( google search a chart for these values )

this shows that florine will pull electrons more strongerly and electrons will be near flourine. this makes F partially negative H partially +.

how to determine if it is polar covalent bond, non polar bond or ionic bond ?

difference between electronegetivities is :

0 to 0.4, then it is non polar covalent bond.

0.4 to 1.6, then it is polar covalent bond.

if it is 1.7 + then it is ionic bond.

so in case of HF,

3.98 - 2.20 = 1.78

therefore HF is ionic bond.

dont get confused in case of Ch4.

because you are only calculating electronegetivity difference in one bond i.e C - H.

  • 1

in CH4,

H

H-C-H

H

C - H bond is non polar covalent bond.

as electroneg of C is 2.55 H is 2.20.

Diff is 0.35. therefore it is a non polar covalent bond .

" non polar " means it has no partial charges on any atoms. they are neutral.

  • 1

thannnnnnnnnnnxxxxxxxxxxxxxx soham! u prooved to be a source of great help,,, the mehod is so easy!!!!!!!!

hats off bro!!!!!

  • 0
What are you looking for?