For the molecules BH, and CIF (Chlorine trifluoridel

For the molecules BH, and CIF (Chlorine trifluoridel. Give a. Total valence electrons b. Lewis structure c. Electron pair geometry d. Molecular geometry e. Bond angle

The Correct Answer and Explanation is :

Let’s analyze each molecule, BH₃ (borane) and ClF₃ (chlorine trifluoride), step by step.

1. BH₃ (Borane)

a. Total Valence Electrons:

• Boron (B) is in Group 13, so it has 3 valence electrons.
• Each hydrogen (H) is in Group 1 and has 1 valence electron.
• Total valence electrons: 3 (from B) + 3 × 1 (from 3 H atoms) = 6 valence electrons.

b. Lewis Structure:

• Boron is the central atom, and three hydrogens are bonded to it.
• Each hydrogen shares a pair of electrons with boron.
• There are no lone pairs on boron or hydrogen atoms.

   H
   |
B—H
   |
   H

c. Electron Pair Geometry:

• Boron has three bonding pairs and no lone pairs of electrons.
• The electron pair geometry is trigonal planar.

d. Molecular Geometry:

• Since there are no lone pairs on boron, the molecular geometry is the same as the electron pair geometry: trigonal planar.

e. Bond Angle:

• In a trigonal planar geometry, the bond angles are 120°.

2. ClF₃ (Chlorine Trifluoride)

a. Total Valence Electrons:

• Chlorine (Cl) is in Group 17, so it has 7 valence electrons.
• Each fluorine (F) is in Group 17 and has 7 valence electrons.
• Total valence electrons: 7 (from Cl) + 3 × 7 (from 3 F atoms) = 26 valence electrons.

b. Lewis Structure:

• Chlorine is the central atom, with three fluorines attached.
• Chlorine has lone pairs, as it is in period 3 and can accommodate more than 8 electrons.
• The structure involves three single bonds between chlorine and fluorine, with two lone pairs on chlorine.

      F
      |
  F—Cl—F
      |
     lone pairs

c. Electron Pair Geometry:

• Chlorine has three bonding pairs and two lone pairs.
• The electron pair geometry is trigonal bipyramidal.

d. Molecular Geometry:

• Due to the lone pairs, the molecular geometry is T-shaped.

e. Bond Angle:

• In a T-shaped molecular geometry, the bond angles are approximately 90° and 180°.

Explanation:

• BH₃ is a simple molecule where boron forms bonds with three hydrogen atoms. Since boron has only three electrons to share, it forms three bonds without any lone pairs, resulting in a trigonal planar geometry with bond angles of 120°.
• ClF₃, on the other hand, has a chlorine atom in the center with three fluorine atoms attached. Chlorine, being in period 3, can hold more than 8 electrons, which results in lone pairs that distort the shape from trigonal bipyramidal to T-shaped, affecting the bond angles to be around 90° and 180°.

These molecular geometries and bond angles reflect the principles of VSEPR (Valence Shell Electron Pair Repulsion) theory, which helps predict the shapes of molecules based on electron repulsion.