0

Guest

Courses New

Why para dihydroxy benzene does not have zero dipole moment while para xylene has. Both r electron donating towards benzene ring.

Why para dihydroxy benzene does not have zero dipole moment while para xylene has. Both r electron donating towards benzene ring.

Grade:12th pass

3 Answers

Umakant biswal
5349 Points
7 years ago
@ dattatray 
the dipole moment of para dimethoxybenzene is not 0 beacuse it exist in two forms , cis and trans forms . 
out of which trans have 0 dipole moment beacuse it is a symmetrical molecule , whereas in the case of cis molecule , it is not completely symmetrical , therefore it have the dipole moment of 2.25 D . 
as in solution , both forms coexist , therefore the observed dipole moment is more than 0 , but less that 2.25 D . 
u can try out this by the structure also . 
HOPE IT CLEARS YOUR DOUBT 
ALL THE BEST , IN CASE OF ANY DOUBT , LET ME KNOW .. 
Dattatray Biradar
10 Points
7 years ago
dear umakant Sir thanks for inputs. However not much clear and my question still remains same - as per book paradimethyl benzene (p-xylene) has zero dipole moment while, paradihydroxy benzene has more than zero. Book says paradihydroxy benzene is non linear and thus dipole moment is not equal to zero. Is there Anything to do with lone pair on oxygen?
Sayan Bhowmik
40 Points
7 years ago
Well It is simple. There are two possible planar configurations of para hydroxyphenol, one having zero dipole moment and the other have very small dipole moment (~1.4 D).Dipole moment is present because there is restricted rotation with the hydroxyl groups.. Dipole moment of O is cancel out but the dipole moment of H is added up as a vector sum bcz the 2 H are not at 180°..I hope my answer clear your doubt.

Think You Can Provide A Better Answer ?

Other Related Questions on Organic Chemistry

View all Questions »

ASK QUESTION

Get your questions answered by the expert for free

Answer and earn gift vouchers

Win Gift vouchers upto Rs 500/-

View courses by askIITians

Design classes One-on-One in your own way with Top IITians/Medical Professionals

Click Here Know More

Complete Self Study Package designed by Industry Leading Experts

Click Here Know More

Live 1-1 coding classes to unleash the Creator in your Child

Click Here Know More

a Complete All-in-One Study package Fully Loaded inside a Tablet!

Click Here Know More