Question

Briefly gives the basic for pauling's scale of electronegativity

Answer 1

Linus Pauling was the original scientist to describe the phenomena of electronegativity. The best way to describe his method is to look at a hypothetical molecule that we will call XY. By comparing the measured X-Y bond energy with the theoretical X-Y bond energy (computed as the average of the X-X bond energy and the Y-Y bond energy), we can describe the relative affinities of these two atoms with respect to each other.

Δ Bond Energies = (X-Y)measured – (X-Y)expected

If the electonegativities of X and y are the same, then we would expect the measured bond energy to equal the theoretical (expected) bond energy and therefore the Δ bond energies would be zero. If the electronegativities of these atoms are not the same, we would see a polar molecule where one atom would start to pull electron density toward itself, causing it to become partially negative.

By doing some careful experiments and calculations, Pauling came up with a slightly more sophisticated equation for the relative electronegativities of two atoms in a molecule: EN(X) - EN(Y) = 0.102 (Δ1/2).1 In that equation, the factor 0.102 is simply a conversion factor between kJ and eV to keep the units consistent with bond energies.

By assigning a value of 4.0 to Fluorine (the most electronegative element), Pauling was able to set up relative values for all of the elements. This was when he first noticed the trend that the electronegativity of an atom was determined by it's position on the periodic table and that the electronegativity tended to increase as you moved left to right and bottom to top along the table. The range of values for Pauling's scale of electronegativity ranges from Fluorine (most electronegative = 4.0) to Francium (least electronegative = 0.7). 2 Furthermore, if the electronegativity difference between two atoms is very large, then the bond type tends to be more ionic, however if the difference in electronegativity is small then it is a nonpolar covalent bond.

Answer 2

HELLO FRIEND HERE IS YOUR ANSWER,,,,,,,,,,

To calculate the required electronegativity of Hydrogen and fluorine are to be found by certain assumptions which can be represented as $X_H$ for Hydrogen and $X_F$ for fluorine respectively. To make this more understandable I've also demonstrated a example.

Now by implying and putting out the Principles of Pauling's formula. Basically it was developed and the relationship between day two of those atoms "A and B" are cordially bonded in together to give the following relationship, it was given by $\bf{Linus \: Pauling}$ who was a American Scientist to find out the difference between electronegativity between two atoms.

$\boxed{\bf{X_A - X_B = 0.1017 \sqrt{\triangle}}}$

Here this $\triangle$ has a separate formula accordingly...

$\boxed{\bf{\triangle = E_{A - B} - \sqrt{E_{A - A} \times E_{B - B}}}}$

Now, all the variables up there, like , $\bf{E_{A - B} \: E_{A - A} \: E_{B - B}}$ are denoting different bind association enthalpies which are expressed by the unit of $\bf{kcal \: mol^{- 1}}$, which basically changes the difference in their respective electronegativities to form a different valued equation altogether of two typical bonded atoms given by this relationship.

$\boxed{\bf{X_A - X_B = 0.208 \sqrt{\triangle}}}$

Whereas when it's representation is done in $\bf{kJ \: mol^{- 1}}$ with the bonds "A and B" or "A--B", "A and A" or "A--A", "B and B" or "B--B" for them respectively. Here, $X_A$ and $X_B$ are denoting their electronegativities of those two elements "A" and "B". If I'd arbitrarily attach a specific numeral value to fluorine as "4.0" which as the highest and most strongest ability to attract stable electrons, all other electronegativities of other elements Lower than that can be calculated.

Here by using that formula of Pauling we've to see the original values of some variables...

$\bf{BE_{H - H} = 104.2 \: kcal \: mol^{- 1}}$

$\bf{BE_{F - F} = 36.6 \: kcal \: mol^{- 1}}$

and,

$\bf{BE_{H - F} = 134.6 \: kcal \: mol^{- 1}}$

These are all bond energies of these elements and atoms of "Hydrogen" and "Fluorine".

Now, using Pauling's formula :

$\bf{| X_H - X_F | = 0.102 \sqrt{\triangle}}$ ; we used this formula because of that unit in $\bf{kJ \: mol^{- 1}}$

Calculate $\triangle$.

$\bf{\triangle = BE (H - F) - \sqrt{BE (H - H) \times BE (F - F)}}$

Substitute the following bond energy values into this equation.

$\bf{= 134.6 - \sqrt{104.2 \times 36.6} \: kcal \: mol^{- 1}}$

$\bf{= 134.6 - \sqrt{3813.72} \: kcal \: mol^{- 1}}$

$\bf{= 134.6 - 61.8 \: kcal \: mol^{- 1}}$

$\bf{= 72.8 \: kcal \: mol^{- 1}}$

Converting $\bf{kcal \: mol^{- 1}}$ to $\bf{kJ \: mol^{- 1}}$.

$\bf{\therefore \: \: = 72.8 \times 4.184 \: kJ \: mol^{- 1}}$

$\bf{= 304.6 \: kJ \: mol^{- 1}}$

Now substitute this to the original equation :

$\bf{\therefore \: \: | X_H - X_F | = 0.012 \sqrt{304.6}}$

$\bf{| X_H - X _F = 0.012 \times 17.4527934727}$

$\bf{\therefore \: \: | X_H - X_F | = 0.102 \sqrt{304.6}}$

$\bf{\therefore \: \: | X_H - X_F | = 1.74}$

Since the Electronegativity of Hydrogen on Pauling's scale is "2.1" or $\bf{X_H = 2.1}$

$\therefore$ As, the value of Electronegativity of Fluorine is higher than that if Hydrogen;

$\bf{X_F = 1.74 + X_H}$

$\bf{\therefore \: \: X_F = 1.74 + 2.1}$

$\boxed{\bf{\therefore \: \: X_F = 3.84 \: or \: 3.8}}$

Likewise, the Electronegativity for Chlorine is $\bf{2.5}$

HOPE THIS HELPS YOU AND SOLVES YOUR DOUBTS FOR CALCULATING ELECTRONEGATIVITY BY USING PAULING'S SCALE!!!!!