Regarding the structure of cyanamide ion, pick out the wrong statement

Options

A. It has one carbon with a negative charge
B. It has two `sigma` bonds
C. It has two `pi` bonds
D. It has two negatively charged Nitrogen atoms

Answer

To determine the wrong statement regarding the structure of the cyanamide ion, we will analyze the structure and characteristics of the cyanamide ion step by step.

### Step 1: Understand the Structure of Cyanamide Ion
Cyanamide ion is derived from cyanamide (NH2CN) by the loss of two hydrogen ions (H+). The structure can be represented as:
- **Cyanamide**: H2N-C≡N
- **Cyanamide Ion**: After losing 2 H+, the structure becomes:
- N≡C-N^(-) (where one nitrogen has a negative charge)

### Step 2: Identify Bonds in the Structure
In the cyanamide ion:
- There is a triple bond between the carbon and one nitrogen (C≡N).
- There is a single bond between the carbon and the other nitrogen (N-C).
- The triple bond consists of one sigma bond and two pi bonds.
- The single bond consists of one sigma bond.

Thus, the bond types in cyanamide ion are:
- **Total Sigma Bonds**: 2 (one from C≡N and one from N-C)
- **Total Pi Bonds**: 2 (from the triple bond C≡N)

### Step 3: Analyze the Statements
Now, let's evaluate the statements provided:
1. **It has one carbon with a negative charge**: This statement is incorrect. The carbon atom in the cyanamide ion does not carry a negative charge; the negative charge is on one of the nitrogen atoms.
2. **It has two sigma bonds**: This statement is correct as we identified two sigma bonds in the structure.
3. **It has two pi bonds**: This statement is also correct since the triple bond consists of two pi bonds.
4. **It has two negatively charged nitrogen atoms**: This statement is incorrect. Only one nitrogen atom carries a negative charge.

### Conclusion
The wrong statement regarding the structure of the cyanamide ion is:
- **It has one carbon with a negative charge.**