Question

when drawing the lewis structure for so4 2-, there are ___ equivalent resonance structures. a 3 b 6 c 5 d 4

Explanation:

Step1: Determine the formula for resonance structures

Resonance structures are different Lewis structures that can be drawn for a molecule or ion. For \(SO_{4}^{2 -}\), we first calculate the total number of valence electrons. Sulfur (S) has 6 valence electrons, each oxygen (O) has 6 valence electrons, and there is a - 2 charge (2 extra electrons). So the total number of valence electrons is \(6+(4\times6)+2 = 32\).

Step2: Draw the basic Lewis structure

The central atom is S. We first form single - bonds between S and each O atom. Each single - bond uses 2 electrons. So far, we have used \(4\times2=8\) electrons. We then distribute the remaining \(32 - 8=24\) electrons as lone pairs on the O atoms (6 electrons on each O atom). But to minimize formal charges, we can form double - bonds. There are 4 equivalent ways to form double - bonds (since all O atoms are equivalent in the sulfate ion).

Answer:

A. 3