Why is it that the bond angle for CBr4 is 109.5?

Answer 1

That is the tetrahedral angle. Each bromine is equivalent and carbon has no lone pairs. Therefore they have to be distributed evenly in space (in 3d space, so it is more than 90 degrees!)

Answer 2

The bond angle for CBr4 is 109.5 degrees because it adopts a tetrahedral molecular geometry due to the presence of four bonding pairs of electrons around the central carbon atom. This arrangement minimizes electron repulsion and maximizes bond angles, resulting in a symmetrical molecule with bond angles of 109.5 degrees.