Which of the following hybrid atomic orbitals would you consider most useful for approximating a molecular orbital scheme around the boron atom in bf3?
select one:
a. sp3
b. 2s and 2p
c. sp2
d. sp

Explanation:

Atomic number of boron = 5

In ground state,

Valence shell electronic configuration of B =

In excited state, one 2s electrons goes into vacant 2p orbital and electronic configuration becomes:

Now, 3 orbitals (2s, and two orbitals of 2p) of B have unpaired electrons. These three orbitals (one 2s, and two orbitals of 2p) undergoes hybridisation to form three hybridised sp2 orbitals.

These 3 hybridised sp2 orbitals are oriented in a trigonal planar arrangement.

The  three hybridised sp2 orbitals overlap with 2p orbital of three F to form three B-F bonds.

here we have to get the change of moles on decrease the volume of the reaction in gas phase.

the   per the given options it will decrease by (d) 11-50%

we know, on decreasing the volume of the gas phase reaction the reaction moves to the product side.

the reaction:                     so₂cl₂ (g) = so₂ (g) + cl₂ (g)         total

the moles at equilibrium:   1 - α                 α               α           = 1+α

concentrations:                   1 - α               α               α           = 1 + α

(concentration = moles/volume, as volume is 1 l)

(where α is the degree of dissociation)

now the dissociation constant in terms of concentration is :

=  

or,

or,   = (at v = 1l)

the reaction:                     so₂cl₂ (g) = so₂ (g) + cl₂ (g)         total

the moles at equilibrium:   1 - α                 α               α           = 1+α

concentrations:               (1 - α)/0.5           α/0.5         α/0.5       = (1 + α)/0.5

thus, the dissociation constant in terms of concentration is :

or,  

=  

so, the change of 1 : 1/0.5

or, 1: 2

thus it will decrease by 50%.

or, as per the given options it will decrease by 11-50%

the answer would be a