What is the value of the bond angles in BCl_3?

• A. 104.5^ext{o}
• B. 90^ext{o}
• C. 120^ext{o}
• D. 109.5^ext{o}

Answer: (C)

Verified step by step guidance

1. Identify the molecular geometry of BCl\_3 by considering the number of bonding pairs and lone pairs around the central boron atom. Boron has three valence electrons and forms three single bonds with chlorine atoms, with no lone pairs on boron.
2. Recognize that with three bonding pairs and no lone pairs, the electron pair geometry is trigonal planar according to VSEPR (Valence Shell Electron Pair Repulsion) theory.
3. Recall that in a trigonal planar geometry, the bond angles between the atoms are all equal and arranged to minimize repulsion, which results in bond angles of 120\^\{\circ\}.
4. Confirm that the absence of lone pairs means no distortion of bond angles, so the ideal bond angle remains 120\^\{\circ\}.
5. Conclude that the bond angles in BCl\_3 are 120\^\{\circ\} due to its trigonal planar shape.