what's the electron domain and molecular geometry of SO3 with a charge of -2?

electron domain= tetrahedral
molecular= trigonal pyramidal
right?

YES, that is correct!

To determine the electron domain and molecular geometry of SO3 with a charge of -2, you will need the Lewis structure of SO3. Here's how you can determine the electron domain and molecular geometry:

1. Start by counting the total number of valence electrons in SO3. Sulfur (S) is in Group 16 of the periodic table, so it contributes 6 valence electrons. Each oxygen (O) atom contributes 6 valence electrons as well. Taking into account the -2 charge, you will add 2 extra electrons. Therefore, the total number of valence electrons is 6 + 3(6) + 2 = 26.

2. Next, draw the Lewis structure of SO3. Place the sulfur atom in the center and connect it with the three oxygen atoms using single bonds. Surround each oxygen atom with its remaining valence electrons. After connecting the atoms and distributing the electrons, you will have the Lewis structure of SO3 with the negative charge distributed on one of the oxygen atoms.

O=S=O
| ||
O O-

3. Determine the electron domain geometry by identifying the positions of electron pairs around the central sulfur atom. In this case, there are two double bonds and one lone pair on the sulfur atom. Thus, the electron domain geometry is tetrahedral, as there are four regions of electron density around the sulfur atom.

4. Finally, determine the molecular geometry by considering the lone pairs and bonded atoms around the central sulfur atom. In SO3, the presence of one lone pair and three bonding pairs leads to the molecular geometry being trigonal pyramidal.

Therefore, the correct electron domain geometry is tetrahedral, and the molecular geometry is trigonal pyramidal for SO3 with a charge of -2.

Actually, the electron domain geometry of SO3 with a charge of -2 is trigonal planar. This is because SO3 has three regions of electron density, which gives it a trigonal planar electron domain geometry.

However, the molecular geometry of a molecule takes into account the presence of lone pairs. Since SO3 has a charge of -2, it means that it has two additional electrons compared to its neutral form. These extra electrons are considered as lone pairs.

When considering the lone pairs, the molecular geometry of SO3 with a charge of -2 is bent (also known as V-shaped) rather than trigonal pyramidal. This is because the two lone pairs on the central sulfur atom distort the geometry, causing it to deviate from the ideal trigonal planar shape.