Question

Draw lewis structure for TeF4, SO2, AsF3, BF3

1. which of the molecules violates the octet rule
2. which of the molecules are trigonal planar.
3. which of the molecules are nonpolar
4. which of the molecules above have 180 bond angles

Answer 1

In the Lewis structures, TeF4 is seesaw shaped, SO2 is bent, AsF3 is trigonal pyramidal, and BF3 is trigonal planar; BF3 violates the octet rule. The only trigonal planar molecule is BF3, which is nonpolar due to its symmetry; SO2 and AsF3 are polar. No molecules listed have 180-degree bond angles.

Step-by-step explanation:

When drawing the Lewis structures for molecules such as TeF4, SO2, AsF3, and BF3, you must consider the total number of valence electrons and how they can be distributed around the central atom to satisfy the octet rule or in some cases where the rule may not apply.

1. TeF4 has a valence electron arrangement that leads to a seesaw shape due to a trigonal bipyramidal electron-pair geometry with one lone pair.
2. SO2 has a bent structure with an sp2 hybridization, which is trigonal planar electron-pair geometry.
3. AsF3 has a trigonal pyramidal shape, with an electron-pair geometry that is tetrahedral.
4. BF3 is trigonal planar both in electron-pair and molecular geometry.

TeF4 does not violate the octet rule but has an expanded octet. Both SO2 and AsF3 obey the octet rule, while BF3 is an example of a molecule that violates the octet rule due to having only six valence electrons around the boron atom.

BF3 is the molecule which is trigonal planar. Regarding polarity, SO2 and AsF3 are polar molecules due to their lack of symmetry and presence of one or more lone pairs leading to a net dipole moment. BF3 is nonpolar since it is symmetrical with all sides being identical and no lone pairs on the central atom, leading to no net dipole moment.

None of the given molecules have 180° bond angles; such angles are characteristic of linear molecular geometries.