Question

number of pi bonds in bf4- ?​

Answer 1

Answer:

The molecular geometry shape of BF

4

−

is , tetrahedral.

Boron has 3 valance electrons and each of the four flourides contributes one electron to each covalent bond. The overall negative charge of the molecule contributes another electron.

Thus overall we have 3+4+1=8 electrons BF

4

−

Answer 2

Answer:

It has 5σ and 2π bonds .

Explanation:

NO+[BF4]−

⇒B.O.ofNO+=3.0, i.e, one sigma bond and two π bonds

∴ No. of π bonds = 2

No. of σ bond = 5

⇒B.O. of NO+=3.0

and B.O. of NO=2.5

Bond order is inversely proportional to bond length.

⇒NO+ is diamagnetic and BF4− is also diamagnetic

⇒B−F bonds are longer in BF4− than in BF3 due to absence of pπ−pπ back bonding in [BF4−]