BH3

Question

BH3 <-- Boron trihydride
If you are to draw a Lewis structure, you would see that just a single bond is needed b/ween each B-H bond. Is Boron coordinate covalent bonding in this situation?

anonymous · Answer

BH3 <-- Boron trihydride
If you are to draw a Lewis structure, you would see that just a single bond is needed b/ween each B-H bond. Is Boron coordinate covalent bonding in this situation? 

Also, its electron configuration before bonding is 1s^2 2s^2 2p^1 
After bonding with those 3 Hydrogens, is its valence configuration going to be: 

1s^2 2s^0 2p^0  OR

Does it hybridize and we get:

[e-, ][e-, ][e-, ] <--- sp^2 [e-, ] <--- p

What I am not understanding is how does Boron's valence configuration change before bonding versus after bonding?

anonymous · Answer

before bonding ur figure will be  trigonal planer but after bonding the correct figure of BH3 will be pyramidal as due to presence of lone pair  angle b/w H-H get decrease that why its str. changes

anonymous · Answer

You did not answer my question.

anonymous · Answer

i still didnt get it what u r saying .. :(

anonymous · Answer

hi since the 2S2 level is paired the hybridization has to take place i.e sp2. after bonding the electrons which have been involved in boding r not used to determine the electron configuration and hence the valence.