Question
How to calculate lone pairs In CO3-2
Answers
GPT-4o mini
To determine the number of lone pairs in the carbonate ion (CO₃²⁻), follow these steps:
1. **Count the total valence electrons:**
- Carbon (C) has 4 valence electrons.
- Each oxygen (O) has 6 valence electrons, and there are three oxygens.
- Additionally, the ion has a -2 charge, which adds 2 more electrons.
Calculation:
\[
\text{Total valence electrons} = 4 + (3 \times 6) + 2 = 4 + 18 + 2 = 24
\]
2. **Draw the Lewis structure:**
- Place the carbon atom in the center and arrange the three oxygen atoms around it.
- Connect each oxygen atom to the carbon with a single bond (C-O). This uses 6 of the 24 electrons (3 pairs for bonds).
- Distributing the remaining electrons starts with fulfilling the octet rule for the oxygen atoms. Each oxygen needs 8 electrons in total.
- Two of the oxygens will each get 6 more electrons (3 lone pairs), while one oxygen will form a double bond with carbon to satisfy the octet requirement.
Here's a representation of the Lewis structure:
- Two oxygens (with -1 formal charge each) are connected with single bonds and have three lone pairs each (6 electrons).
- One oxygen (with a formal charge of 0) is connected with a double bond (2 bonding electrons) and has two lone pairs (4 electrons).
3. **Count the lone pairs:**
- The two oxygens that are singly bonded each have 3 lone pairs.
- The oxygen that is double bonded has 2 lone pairs.
Total lone pairs:
\[
2 \text{ (from each of the two –O)} \times 3 + 2 \text{ (from the double-bonded –O)} = 3 + 3 + 2 = 8 \text{ lone pairs}
\]
4. **Conclusion:**
In the Lewis structure of the carbonate ion (CO₃²⁻), there are a total of 8 lone pairs of electrons, distributed among the three oxygen atoms.
1. **Count the total valence electrons:**
- Carbon (C) has 4 valence electrons.
- Each oxygen (O) has 6 valence electrons, and there are three oxygens.
- Additionally, the ion has a -2 charge, which adds 2 more electrons.
Calculation:
\[
\text{Total valence electrons} = 4 + (3 \times 6) + 2 = 4 + 18 + 2 = 24
\]
2. **Draw the Lewis structure:**
- Place the carbon atom in the center and arrange the three oxygen atoms around it.
- Connect each oxygen atom to the carbon with a single bond (C-O). This uses 6 of the 24 electrons (3 pairs for bonds).
- Distributing the remaining electrons starts with fulfilling the octet rule for the oxygen atoms. Each oxygen needs 8 electrons in total.
- Two of the oxygens will each get 6 more electrons (3 lone pairs), while one oxygen will form a double bond with carbon to satisfy the octet requirement.
Here's a representation of the Lewis structure:
- Two oxygens (with -1 formal charge each) are connected with single bonds and have three lone pairs each (6 electrons).
- One oxygen (with a formal charge of 0) is connected with a double bond (2 bonding electrons) and has two lone pairs (4 electrons).
3. **Count the lone pairs:**
- The two oxygens that are singly bonded each have 3 lone pairs.
- The oxygen that is double bonded has 2 lone pairs.
Total lone pairs:
\[
2 \text{ (from each of the two –O)} \times 3 + 2 \text{ (from the double-bonded –O)} = 3 + 3 + 2 = 8 \text{ lone pairs}
\]
4. **Conclusion:**
In the Lewis structure of the carbonate ion (CO₃²⁻), there are a total of 8 lone pairs of electrons, distributed among the three oxygen atoms.