Questions: Draw the Lewis structure for a thiol (SH-) ion.

Transcript text: Draw the Lewis structure for a thiol $\left(\mathrm{SH}^{-}\right)$ion.

Solution

Solution Steps

Step 1: Determine the Total Number of Valence Electrons

To draw the Lewis structure for the thiol ion $\mathrm{SH}^{-}$, we first need to determine the total number of valence electrons. Sulfur (S) is in group 16 and has 6 valence electrons. Hydrogen (H) has 1 valence electron. The negative charge on the ion indicates an additional electron.

\[ \text{Total valence electrons} = 6 (\text{from S}) + 1 (\text{from H}) + 1 (\text{extra electron for the charge}) = 8 \]

Step 2: Draw the Basic Structure

The basic structure of the thiol ion involves a single bond between the sulfur and hydrogen atoms.

\[ \mathrm{S} - \mathrm{H} \]

Step 3: Distribute Remaining Electrons

After forming the $\mathrm{S} - \mathrm{H}$ bond, which uses 2 electrons, we have 6 electrons remaining. These electrons will be placed as lone pairs on the sulfur atom to satisfy its octet.

Step 4: Complete the Lewis Structure

Place the remaining 6 electrons as three lone pairs around the sulfur atom:

\[ \begin{array}{c} \cdot \cdot \\ \mathrm{H} - \mathrm{S}^{-} \\ \cdot \cdot \end{array} \]