Here are the molecular shapes and predicted bond angles for PF3, COCl2, and CS2:
a) PF3 (Phosphorus Trifluoride)
Molecular Shape: Trigonal Pyramidal
Bond Angle: Approximately 107 degrees
Explanation: PF3 has a central phosphorus atom bonded to three fluorine atoms and one lone pair of electrons. The lone pair repels the bonding pairs, causing the bond angles to be slightly less than the ideal 109.5 degrees of a tetrahedral arrangement.
b) COCl2 (Phosgene)
Molecular Shape: Trigonal Planar
Bond Angle: Approximately 120 degrees
Explanation: COCl2 has a central carbon atom double-bonded to an oxygen atom and single-bonded to two chlorine atoms. The molecule is planar, and the bond angles are close to the ideal 120 degrees due to the absence of lone pairs on the central atom.
c) CS2 (Carbon Disulfide)
Molecular Shape: Linear
Bond Angle: 180 degrees
Explanation: CS2 has a central carbon atom double-bonded to two sulfur atoms. The molecule is linear, and the bond angle is exactly 180 degrees due to the symmetrical arrangement of the atoms.