The driving force is because HCl and SO2 are gases? find any values for SO2 when it is in liquid phase.

According to the the table, the driving force is because HCl and SO2 is gases. Check this up with calculate the reaction enthalpy and reaction entropy at 298K. If you need more data will you have to check it up in a table work

HCOOH+ClSOCl -> HCOCl+HCl+SO2

ClS(O)Cl (aq): Delta Hf -785 (kJ/mol) Sm 220 (J/K/mol)
HC(O)Cl(aq) :Delta Hf -376.56 (kJ/mol) Sm 246.52 (J/K/mol)

Check up values for HCOOH, SO2 and HCl

HCOOH (aq): Delta Hf -424,72 (kJ/mol) Sm 128,95 (J/K/mol)
HCl(q) :Delta Hf -92,31 (kJ/mol) Sm 186,91 (J/K/mol)
SO2(q) :Delta Hf -296,83 (kJ/mol) Sm 248,22
(J/K/mol)
HCl(aq) :Delta Hf -167,16 (kJ/mol) Sm 56,5 (J/K/mol)
SO2(aq) : No values

Delta Hf= -376,56-92,31-296,83-(-424,72-785)= 444,02 KJ/mol

Delta S= 246,52+186,91+248,22-128,95-220=332,7 J/K/mol

When delta H and delta S are positive the reaction is entropy driven if SO2 and HCl are in gas phase.

BUT how can check up if the the driving force is because HCl and SO2 are gases? why not find any values for SO2 when it is in liquid phase