Question

An alternative definition of electronegativity is: Electronegativity = constant (I.E. – E.A.)where I.E. is the ionization energy and E.A. is the electron affinity. Using the data below, calculate the electronegativity of Cl. Hint: You may assume that the electronegativity of F is defined to be 4.0.

Answer 1

The missing data is the value of I.E and E.A for Cl and F, which are, Cl: I.E =1255 kJ/mol, E.A = -348.7 kJ/mol, F: I.E = 1678 kJ/mol, E.A = -327.8 kJ/mol.

Answer:

3.2

Explanation:

The electronegativity is the capacity of an atom to attract an electron in a bond. As higher is it, as higher the electron will be attracted. The ionization energy is the minimum energy necessary to remove one electron of the atom, transforming it on a cation. On the other hand, the electron affinity is the energy that is lost when the atom gains an electron and is transformed on an anion.

Calling the constant as K, and knowing that the electronegative of fluorine (F) is 4.0:

4 = K*(1678 - (-327.8))

2005.8K = 4

K = 2.00x10⁻³ mol/kJ

Thus, for chlorine (Cl):

Electronegativity = 2.00x10⁻³*(1255 - (-348.7))

Electronegativity = 3.2