Question

Electronegativity of F on Pauling's scale is 4.0. The value on Mulliken's scale is:
A 11.2
B 14.4
C 16.8
D None of these

Answer 1

Hint: We know electronegativity is the ability of an atom, within a molecule to attract the electrons towards itself. The electronegativity value of elements is expressed on a number of arbitrary scales such as Pauling’s scale , Mulliken’s scale etc.

Complete step by step answer:
As we know that in a covalent compound such as hydrogen fluoride, the electrons that are shared between hydrogen and fluorine are not present in the midway. The drift of the electron is affected by the atom and varies from atom to atom. Here since fluorine has greater nuclear than hydrogen, the bonding pair drifts more close to the fluorine atom and goes away from the hydrogen atom. As a result fluorine acquires a small negative charge and hydrogen acquires a small positive charge.
To determine the value of electronegativity different scales were given. Pauling’s scale and Mulliken’s scale are related to each other by the following equation.

${\chi _P} = 0.336({\chi _M} - 0.615)$

Here Mulliken’s electronegativities,${\chi _M}$ are related to Pauling’s values,${\chi _P}$by the above equation.
We have given that electronegativity of F on Pauling's scale is 4.0. So to find the electronegativity on Mulliken’s scale, put ${\chi _P} = 4$ in the above equation.

$4 = 0.336({\chi _M} - 0.615)$

After solving the above equation we get, ${\chi _M} = 11.2$.

So, the correct answer is Option A.

Note: It should be noted that there is a difference between electron affinity and electronegativity as said earlier electronegativity is the tendency of an atom within a molecule to attract molecule, whereas electron affinity is defined as the energy change when an electron is added to an isolated gaseous atom.