Account for the following: a. Ozone is thermodynamically unstable.b. Solid PCl5 is ionic in nature.c. Fluorine forms only one oxoacid HOF .


Ozone decomposes to form one oxygen molecule and a nascent oxygen atom.
This reaction is an exothermic reaction i.e. enthalpy(H) is negative and there is also an increase in the entropy(S) as the disorderness is increasing.
ΔG =ΔH -TΔS
From the above equation as ΔH and TΔS are both negative then ΔG is also negative i.e. the above reaction is spontaneous i.e. ozone is thermodynamically unstable.
Solid PCl5 is ionic in nature as it exists in ion form as [PCl4]+[PCl6]-.
Fluorine is the most electronegative element of the periodic table and it is also small in size, so it only exists in the -1 oxidation state and can form only one oxoacid HOF.

Final Answer:
Ozone is a pungent-smelling gas and is one of the allotropes of oxygen which is thermodynamically less stable than oxygen.
Solid PCl5 is ionic in nature as it exists in ion form as [PCl4]+[PCl6]-.
Fluorine is the most electronegative element of the periodic table and it is also small in size, so it only exists in the -1 oxidation state and can form only one oxoacid HOF.