Fluorine reacts with sulfur to form several different covalent compounds. Three of these compounds are \(\mathrm{SF}_{2}, \mathrm{SF}_{4},\) and \(\mathrm{SF}_{6} .\) Draw the Lewis structures for these compounds, and predict the molecular structures (including bond angles). Would you expect \(\mathrm{OF}_{4}\) to be a stable compound?

First, we need to find the total number of valence electrons for sulfur and fluorine in each compound. Sulfur belongs to Group 16 and has 6 valence electrons. Fluorine belongs to Group 17 and has 7 valence electrons. Compound SF2: Total valence electrons = 6 (Sulfur) + 2 * 7 (Fluorine) = 6 + 14 = 20 electrons Compound SF4: Total valence electrons = 6 (Sulfur) + 4 * 7 (Fluorine) = 6 + 28 = 34 electrons Compound SF6: Total valence electrons = 6 (Sulfur) + 6 * 7 (Fluorine) = 6 + 42 = 48 electrons

For each compound, we will connect sulfur (central atom) to fluorine atoms with single bonds and fill in the remaining electrons to satisfy the octet rule: Compound SF2: Sulfur has one bond to each of the two fluorines, using 4 electrons. We can arrange the remaining 16 electrons in 8 lone electron pairs: \[ \mathrm{F} -\mathrm{S}-\mathrm{F} \] where each F atom has 3 lone pairs. Compound SF4: Sulfur has one bond to each of the four fluorines, using 8 electrons. We can arrange the remaining 26 electrons in 13 lone electron pairs: \[ \mathrm{F}_{2} \mathrm{S}(\mathrm{F}_{2}) \] where each F atom has 3 lone pairs, and the S has one lone pair. Compound SF6: Sulfur has one bond to each of the six fluorines, using 12 electrons. We can arrange the remaining 36 electrons in 18 lone electron pairs: \[ \mathrm{F}_{3} \mathrm{S}(\mathrm{F}_{3}) \] where each F atom has 3 lone pairs.

We will use the Valence Shell Electron Pair Repulsion (VSEPR) theory to determine the molecular structure and bond angles. Compound SF2: There are 2 bonding domains and 1 lone pair around the sulfur atom, resulting in a bent molecular structure and a bond angle of approximately 104.5 degrees. Compound SF4: There are 4 bonding domains and 1 lone pair around the sulfur atom, resulting in a seesaw molecular structure. The bond angle between axial fluorine atoms and sulfur_atom is 180 degrees, whereas the bond angle between equatorial fluorine atoms and the sulfur atom is 120 degrees. Compound SF6: There are 6 bonding domains and no lone pairs around the sulfur atom, resulting in an octahedral molecular structure and bond angles of 90 degrees and 180 degrees.

Oxygen belongs to Group 16 and has 6 valence electrons. If we were to construct the Lewis structure for OF4, we would find that oxygen has 2 lone pairs of electrons and is connected to the four fluorine atoms with single bonds. This would result in a total of 14 electrons surrounding the oxygen atom, which violates the octet rule. Therefore, OF4 is not expected to be a stable compound.