What is the orbital hybridization in BrCl3?

In bromine trichloride, or ##BrCl_3##, the bromine atom is ##sp^3d## .

Start by drawing the of the compound. The total number of will be 28, 7 from each of the three chlorine atoms and 7 from the bromine atom.

Out of the 28 , 24 will be used to complete the of the chlorine atoms - each chlorine atom has 3 lone pairs and shares single bond with bromine.

As you can see, the remaining 4 are placed on bromine as lone pairs. This means that bromine will have a total of 10 valence electrons, which is possible because it can have an expanded .

The of the bromine atom is determine by counting the regions of electron that surround the atom - this represents the steric number.

So, bromine has 2 lone pairs, and 3 single bonds, which means it has a steric number of 5. The steric number will also tell you how many hybrid orbitals an atom has. In this case, 5 hybrid orbitals would correspond to an ##sp^3d## hybridized atom.

Because of the two lone pairs of electrons, the of the bromine trichloride molecule will be T-shaped, not trigonal bipyramidal.