Consider an ion with the following structure : `[H_2C=C=NH_2]^+` For this ion , we can define two planes : one plane containing H-C-H group , the other plane containing H-C-H group , what is the relationship between these planes ?

Options

A. They are at `120 ^0`
B. They are perpendicular to each other
C. They are in the same plane
D. More information is required

Answer

To determine the relationship between the two planes in the ion structure `[H2C=C=NH2]^+`, we can analyze the geometry of the molecule step by step.

### Step-by-Step Solution:

1. **Identify the Structure**: The ion can be represented as `H2C=C=NH2+`. Here, we have two carbon atoms (C) connected by a double bond, and one of the carbons is also connected to a nitrogen atom (N) with another double bond.

2. **Define the Planes**:
- The first plane contains the H-C-H group (the two hydrogen atoms attached to the first carbon).
- The second plane contains the H-N-H group (the two hydrogen atoms attached to the nitrogen).

3. **Analyze the Geometry**:
- The central carbon atom (C) is involved in a double bond with another carbon atom and a double bond with a nitrogen atom.
- The geometry around the carbon atoms in a double bond is typically planar due to the sp² hybridization, which allows for a trigonal planar arrangement.

4. **Compare with Allene Structure**:
- The structure can be compared to an Allene (C=C=C) system, where the terminal groups (in this case, H and NH2) are positioned in perpendicular planes.
- In an Allene, the terminal groups are oriented at 90 degrees to each other, indicating that the planes formed by these groups are also perpendicular.

5. **Conclusion**:
- Since the geometry of the `[H2C=C=NH2]^+` ion is similar to that of an Allene, we can conclude that the plane containing the H-C-H group and the plane containing the H-N-H group are also perpendicular to each other.

### Final Answer:
The relationship between the two planes is that they are **perpendicular to each other**.