When PCl5 solidifies it forms PCl4 + cations and PCl6 - anions. According to valence bond theory, what hybrid orbitals are used by phosphorus in the PCl4 + cations?

sp³

Explanation:

Hybrid orbitals is the term used to describe the process resulting from the hybridization of orbals that promotes the creation of new orbitals in two atoms that are called hybrid orbitals because they are exactly the same, in number.

When these orbitals are generated, it is common for their origins to be at atomic sub-levels, mainly the "s" level and the "p" level, giving rise to the sp, sp² and sp³ orbitals.

The sp³ hybrid orbital, for example, is used by phosphorus in PCl4 + cations.

sp³

Explanation:

Number of hybrid orbitals = (V + S - C + A) / 2

Where

H is the number of hybrid orbitals

V is the valence electrons of the central atom = 5

S is the number of single valency atoms = 4

C is the number of cations = 1

A is the number of anions = 0

For PCl₄⁺

Applying the values, we get:

H = (5+4-1+0) / 2

= 4

This corresponds to sp³ hybridization.