List SOF2, SO2F-, and S2O3^-2 in order of increasing sulfur-to-oxygen bond length.
How do u tell by just looking at the Lewis structures?
Draw the Lewis electron dot structure. Single bonds are longer than double bonds are longer than triple bonds. Where resonance structures appear you will have something between single and double bonds; i.e., it will be shorter than a single bond but longer than a double bond.
To determine the order of increasing sulfur-to-oxygen bond length by looking at the Lewis structures, we need to consider the number of lone pairs on the central sulfur atom and the formal charges on the atoms involved.
First, let's draw the Lewis structures for each of the molecules:
1. SOF2: In this compound, sulfur (S) is bonded to two oxygen (O) atoms and one fluorine (F) atom. The Lewis structure would show a central sulfur atom bonded to two oxygen atoms and one fluorine atom. The oxygen atoms will have two lone pairs each.
2. SO2F-: In this compound, sulfur is bonded to two oxygen atoms and one fluorine atom, but it also carries a negative charge (an extra electron). The Lewis structure would show a central sulfur atom bonded to two oxygen atoms and one fluorine atom. The oxygen atoms will have two lone pairs each.
3. S2O3^-2: In this compound, there are two sulfur atoms bonded to three oxygen atoms and it carries a charge of -2 (two extra electrons). The Lewis structure would show two sulfur atoms, each bonded to one oxygen atom, and with one sulfur-oxygen double bond. The oxygen atoms will have one lone pair each.
Now, let's analyze them based on the factors mentioned earlier:
- The number of lone pairs on the central atom: The more lone pairs on the central atom, the shorter the bond length usually becomes. This is because lone pairs create more electron-electron repulsion, which pushes away the bonded atoms, resulting in longer bond lengths.
- Formal charges: The presence of formal charges can affect the overall charge distribution in a molecule or ion, potentially changing the bond lengths.
Considering these factors, we can conclude that the order of increasing sulfur-to-oxygen bond length is as follows:
1. SO2F- < SOF2 < S2O3^-2
In SO2F-, both oxygen atoms have two lone pairs, leading to increased repulsion and longer bond lengths compared to SOF2. In S2O3^-2, the oxygen atoms only have one lone pair each, resulting in shorter bond lengths when compared to both SO2F- and SOF2.