The question is which of the following acid is polar?
a) HF
b) HCl
c) HNO3
d) H2SO4
The sir drawn Lewis structure of these molecules and showed formal charges on HNO3 and told that it is the only polar acid in isolated state. Please refer the attached image ( I have corrected it by extra marking that in HNO3 all atoms complete octet obviously except H).
I guess he dont know what is polar and non-polar. All above molecules have net-dipole moment associated with them so all should be polar in nature. even my teacher told one controversial statement -"water is non-polar in isolated state”
he believes - “formal charges are real charges due to electrons. Formal charge is the criterion to detect polar and non-polar molecules. “When I said - dipole moment is the only criterion to detect polarity and formal charges are not real but hypothetical charges to keep track of electrons, he disagree.
what you guys think about my answer provided by chemistry teacher?

Shivraj, 7 years ago

Grade:12th pass

2 Answers

Suraj Singh

148 Points

7 years ago

Hy shivrajThe polar nature of any compound is dicided by 3 factors 1) the central atom should not have any lone pair 2)all the groups attached to it should be same 3) the dipole moment should be zero... SO in tha above acids HF, HCl, HNO3 are polar.. In HF and HCl their is electronegativity order show dipole moment exists in such cases.. In the 3rd one their is a double bond, a single bond and a dative bond.. The electronegativity of double bond is more than the other 2 so their is dipole moment... But H2SO4 non polar as it`s dipole moment is 0... Hope U like it

Shivraj

10 Points

7 years ago

I agreed that HF, HCl and HNO3 are polar but H2SO4 is also polar acid. The S is tetrahedral and all bonds are not same bond so dipoles don't cancels out and resultant dipole of H2SO4 is 2.9 Debye units