Question

1. Predict whether each compound in your assigned set of substances is polar or nonpolar [NOTE OF CLARIFICATION: a polyatomic ion may be considered polar or nonpolar. An ion is charged, meaning it has a different number of electrons vs protons; something is polar, on the other hand, if its electron density is unevenly distributed over its structure. Soluble ionic substances will dissolve in polar solvents and not nonpolar solvents (whether or not the individual ions are polar or not) because the indidual ions are charged]

Assigned set of substances:

CIF2O2+

SCI2

BrF6+

Sel3+

ICI2-

SO2

SeBr4

CIF4-

Answer 1

1) ClF2O2+: In this compound the atoms Cl, F and O have different electronegativity as well as it is a cation overall, hence it is a polar compound.

2) SCl2: Cl-S-Cl is not a linear molecule, SCl2 has a 'bent' structure. This is because lone pairs of electrons on S which have greater repulsion, and therefore the dipole moment do not cancel out, which makes the molecule is polar.

3) BrF6+ : this is AB₆ type molecule, with octahedral geometry. All F equally attracts the electrons towards themselves equally hence it is nonpolar.

4) SeI3+ : the molecule is a cation and so it is polar.

5) ICl2-: The molecule has two identical non-central atoms. The structure is linear, giving dipoles that are opposite in direction to each other. The three lone pairs of electrons are 120^∘ away from each adjacent one, a rotationally-symmetric configuration; so, the lone-pair-bonding-pair repulsions sum to cancel out as well. Even if the electronegativity difference is between Cl and I; the dipoles all cancel out to give a net dipole moment of zero in all directions. Therefore, ICl−2 is nonpolar.

6) SO2: S=O bonds are polar due to electronegativity difference between the two elements. The SO2 molecule has a bent structure. It has a net dipole moment, which is the resultant vector of the two S-O moments. Therefore, SO2 is polar.

7) SeB4: Equal distribution of electrons make is non-polar.

8) ClF4-: asymmetrical distribution of electrons particular lone pair of electrons if central Cl atoms make it polar.