Lewis Structure for OPBr3?

I can’t figure out how to answer this question on masteringchemistry.com I have tried drawing the O and Br single bonded to the P with 3 sets of unbonded valence electrons to each O and Br but it says I am wrong. Here is the actual question:

Draw the lews structure for OPBr3.

Draw the molecule by placing atoms on the grid and connecting them with bonds. Include all lone pairs of electrons.


P,O and Br, has 5, 6 and 7 valence electron, respectively, so we have 32 valance electron

P is center atom

O and Br must have 8 electron around each

the number of electron P have after bonding is: 18 – 1( number of O)x8 – 3(number of Br)x8 = 0

with 4 atoms round it, OPBr3 has tetrahedral geometry

the electron structure of this molecule is






Here it is, so it makes more sense

I just did this problem and got it right.

I would have gotten it right first time if I hadn’t forgotten the electrons, LOL

So don’t do what I did and forget to put the electrons, xD

but here is the answer and it said it was right

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