Respuesta :
It's polar because electronegativities of As and Br are different.
Answer : [tex]AsBr_3[/tex] is a polar molecule.
Explanation :
First we have to determine the hybridization of [tex]AsBr_3[/tex].
Formula used :
[tex]\text{Number of electron pair}=\frac{1}{2}[V+N-C+A][/tex]
where,
V = number of valence electrons present in central atom
N = number of monovalent atoms bonded to central atom
C = charge of cation
A = charge of anion
[tex]\text{Number of electron pair}=\frac{1}{2}\times [5+3]=4[/tex]
Bond pair electrons = 3
Lone pair electrons = 4 - 3 = 1
The number of electron pair are 4 that means the hybridization will be [tex]sp^3[/tex] and the electronic geometry of the molecule will be tetrahedral.
But as there are three atoms around the central arsenic atom, the fourth position will be occupied by lone pair of electrons. The repulsion between lone and bond pair of electrons is more and hence the molecular geometry will be trigonal pyramidal.
Polar bond : It is defined as the covalent bonds in which the electrons are shared unequally (that result in partial charges) between the elements that have different electronegativity. In the polar bond, the electron cloud is in distorted form. Polar bonds have a dipole moment.
Non-polar bond : It is defined as the covalent bonds in which the electrons are shared equally (that result no charges) between the elements that have same electronegativity. In the non-polar bond, the electron cloud is not in distorted form. Non-polar bonds do not have a dipole moment.
In the given molecule, there is some dipole moment due to asymmetric molecule. So, the given molecule is polar.
Hence, [tex]AsBr_3[/tex] is a polar molecule.
