Answer:
Explanation:
The polarity of the bonds in HCCl3 can be determined via the concept of electronegativity and bond type.
Electronegativity of an element is the property that combines the ability of its atom to lose and gain electrons(s).It is quantitatively expressed in terms of a number that measures the relative tendency with which the atoms of the element attract valence electrons in a chemical bond.
However another important aspect of electronegativity is the prediction of bond type that could be present between atoms or two elements of known electronegativities. If we consider an elements A and B with electronegative difference [tex]x_A \ and \ x_B[/tex] respectively. The electronegative difference [tex]\Delta x = x_A - x_B[/tex]
If [tex]\Delta x=0[/tex] , then element A and element is the same and the molecule formed is symmetrical , thus the bond type is non-polar
If [tex]\Delta x[/tex] is small; i.e constitute a relative little difference in electronegative values, the molecule formed is unsymmetrical and so the formation of a partial charge occurs or a dipole exists along the bond. Thus this is said to be polar.
In HCCl3, the electronegativity of element C = 2.5, H = 2.1 and Cl = 3.0
Then; [tex]\Delta x = x{C} - x{H}[/tex]
[tex]\Delta = 2.5 -2.1 = 0.4[/tex]
The bond between them is said to be non - polar.
Likewise between C and Cl; the electronegative difference is 0.5 , thus the bond between Carbon and Chlorine is said to be polar.
Howeve, since the three Cl polar bonds are not symmetrical, they do not cancel each dipole , thus the molecule has a net dipole. Therefore the entire molecule HCCl3 is said to be polar.
