Question

Which compound is the most polar?

hf
SO2
co
f2​

Answer 1

HF.

Step-by-step explanation:

The most polar compound would have the greatest overall dipole moment. Out of all the choices, we can easily eliminate
`F_2` as our choice, as it's non-polar. Polarity may be evaluated by estimating the electronegativity difference between the given atoms. A bond between the same atoms would be considered non-polar, as electronegativity of each fluorine atom is the same giving a net difference of 0 and a non-polar molecule.

The remaining 3 substances are polar. HF consists of hydrogen of an average electronegativity and the most electronegative atom in the periodic table, fluorine, so the bond is highly polarized. Similarly, fluorine contains 3 lone pairs inducing even greater polarity than just the electrons within the bond.

Sulfur dioxide may seem as non-polar due to the symmetry of a molecule. However, the lone pair on sulfur makes it polar, but the electronegativity difference between sulfur and oxygen is much lower, as sulfur and oxygen are in the same group of the periodic table.

Carbon monoxide is polar, as oxygen is more electronegative than carbon, so the electrons are polarized towards oxygen with one lone pair. The electronegativity difference between carbon and oxygen, however, isn't as high as between H and F, as carbon and oxygen are close to each other in the periodic table.

Answer 2

HF

Step-by-step explanation:

The polarity of a molecule depends on its shape and on the polarity of its bonds.

The bond polarity, in turn, depends on the electronegativity difference (ΔEN) between the bonded atoms.

For HF, ΔEN = 1.78

For SO₂, ΔEN = 0.86. SO₂ has two S-O bonds, but they are at an angle of 119° to each other, so they partially cancel.

For CO, ΔEN = 0.89

For F₂, ΔEN = 0