Draw the lewis structure for the chlorate ion, clo3- that meets the octet rule
The Correct Answer and Explanation is :
To draw the Lewis structure for the chlorate ion (ClO₃⁻), we need to consider the following steps and principles, including the octet rule.
Steps to Draw the Lewis Structure for ClO₃⁻:
- Count the Total Valence Electrons:
- Chlorine (Cl) has 7 valence electrons.
- Each oxygen (O) atom has 6 valence electrons, and there are three oxygen atoms: 3 × 6 = 18.
- The chlorate ion has an overall charge of -1, which adds one more electron.
- Total: (7 + 18 + 1 = 26) valence electrons.
- Arrange the Atoms:
- Place Cl in the center as the central atom, surrounded by three O atoms.
- Draw Single Bonds:
- Connect each O atom to Cl with a single bond. This uses 6 electrons (3 bonds × 2 electrons per bond), leaving (26 – 6 = 20) electrons.
- Distribute Remaining Electrons:
- Distribute the remaining electrons to the oxygen atoms to satisfy the octet rule.
- Place 6 electrons (3 lone pairs) on each of the three oxygen atoms, consuming (3 \times 6 = 18) electrons. Now we have (20 – 18 = 2) electrons left.
- Complete the Octet for Chlorine:
- Since the central Cl atom can expand its octet, we can convert one of the lone pairs from one of the oxygen atoms into a double bond with chlorine.
- This means one oxygen will now be double-bonded to chlorine.
- Now we have two O atoms with 6 electrons each (3 lone pairs) and one O atom double-bonded with chlorine (with 4 electrons around it: 2 in the bond and 2 lone pairs).
- Charge Representation:
- Assign a formal charge to the atoms. In this structure, the central Cl will have a formal charge of +1, while one O atom with a single bond will have -1, and the two remaining O atoms will have a formal charge of 0. This results in an overall charge of -1 for the ion.
Final Lewis Structure
The final Lewis structure for ClO₃⁻ shows a central Cl atom double-bonded to one O atom and single-bonded to the other two O atoms. Each single-bonded oxygen has three lone pairs, while the double-bonded oxygen has two lone pairs. This structure meets the octet rule for all atoms involved, with Cl exceeding the octet as it is in period 3 and can have more than eight electrons in its valence shell.
Summary
In conclusion, the Lewis structure of the chlorate ion satisfies the octet rule for oxygen atoms and allows chlorine to expand its octet. The correct representation shows how valence electrons are distributed to ensure stability and satisfaction of the octet rule.