The non planar molecule among the following is

Options

A. `B_2 H_6`
B. `C_2 H_4`
C. `C_6 H_6`
D. `BCl_3`

Answer

To determine which molecule among the given options is non-planar, we will analyze the molecular structures and hybridizations of each compound.

### Step 1: Analyze B2H6 (Diborane)
- **Structure**: Diborane (B2H6) consists of two boron atoms and six hydrogen atoms. The structure is such that:
- Each boron atom is bonded to four hydrogen atoms.
- Two of the hydrogen atoms are bridge hydrogens, which connect the two boron atoms.
- The other four hydrogen atoms are terminal hydrogens.
- **Hybridization**: The hybridization of boron in B2H6 is sp³. This means that:
- The terminal hydrogens are in the same plane as the boron atoms.
- The bridge hydrogens are positioned above and below this plane, making the overall structure non-planar.

### Step 2: Analyze C2H4 (Ethylene)
- **Structure**: Ethylene (C2H4) consists of two carbon atoms double-bonded to each other, with each carbon atom bonded to two hydrogen atoms.
- **Hybridization**: The hybridization of each carbon atom in C2H4 is sp². This results in a planar structure, as all atoms lie in the same plane.

### Step 3: Analyze C6H6 (Benzene)
- **Structure**: Benzene (C6H6) is a cyclic compound with six carbon atoms bonded in a ring, with alternating double bonds.
- **Hybridization**: Each carbon atom in benzene is also sp² hybridized. The planar arrangement of the carbon atoms and the delocalized π electrons contributes to the planar structure of benzene.

### Step 4: Analyze BCl3 (Boron Trichloride)
- **Structure**: BCl3 consists of one boron atom bonded to three chlorine atoms.
- **Hybridization**: The hybridization of boron in BCl3 is sp², leading to a trigonal planar geometry. All atoms in BCl3 are in the same plane.

### Conclusion
After analyzing all the molecules:
- B2H6 is the only non-planar molecule due to the presence of bridge hydrogens that are positioned above and below the plane of the terminal hydrogens and boron atoms.
- C2H4, C6H6, and BCl3 are all planar.

Thus, the non-planar molecule among the options is **B2H6**.