BCl3 molecule is planar while NCl3 is pyramidal becausea)BCl3 does not...
BCl3 is planar as boron does not have lone pair of electrons on it, so its steric no. comes out to be 3 , by which we know that its hybridization will be sp2 ( geometry planar ) , whereas. for NCl3 ,N has lone pair of electrons on it so its steric no. will. be 4, that is, sp3 hybridization and so its geometry will be tetrahedral ..
BCl3 molecule is planar while NCl3 is pyramidal becausea)BCl3 does not...
Explanation:
1. BCl3:
BCl3 is a molecule that consists of one boron atom and three chlorine atoms. Boron has an atomic number of 5 and its electronic configuration is 1s2 2s2 2p1. It has an incomplete octet and thus can form only three bonds. In BCl3, boron forms three sigma bonds with the three chlorine atoms, resulting in a trigonal planar shape.
2. NCl3:
NCl3 is a molecule that consists of one nitrogen atom and three chlorine atoms. Nitrogen has an atomic number of 7 and its electronic configuration is 1s2 2s2 2p3. It has five valence electrons and can form three sigma bonds. In NCl3, nitrogen forms three sigma bonds with the three chlorine atoms, similar to BCl3. However, nitrogen also has one lone pair of electrons on it.
3. Lone pair of electrons:
The presence of a lone pair of electrons on the central atom in NCl3 makes it pyramidal in shape. The lone pair of electrons occupies more space and repels the bonding pairs, causing the molecule to adopt a pyramidal shape with a bond angle of approximately 107 degrees. In contrast, BCl3 does not have a lone pair of electrons on the boron atom, so it adopts a planar shape with a bond angle of 120 degrees.
4. Effect of lone pair:
The lone pair of electrons on the nitrogen atom in NCl3 creates an electron cloud that is not symmetrical around the central atom. This leads to an imbalance in the distribution of electron density, resulting in a slightly polar molecule. In contrast, BCl3 does not have a lone pair of electrons, so the electron density is symmetrical around the boron atom, making it a nonpolar molecule.
5. Conclusion:
The presence of a lone pair of electrons on the central atom in NCl3 and the absence of a lone pair of electrons on the central atom in BCl3 are the main reasons for the difference in their shapes. BCl3 is planar due to the absence of a lone pair, while NCl3 is pyramidal due to the presence of a lone pair.