From the given information
ΔH is negative so it means dissolution of gas HCl(g) is exothermic.
HCl(g)+10H2O(l)→HCl.10H2O ...(1)
ΔH1=−69.01 mol kJ
HCl(g)+40H2O(l)→HCl.40H2O ...(2)
ΔH2=−72.79 mol kJ
Hence heat of solution depends upon amount of solvent
By equation..(2) - equation
HCl.10H2O+30H2O(ℓ)→HCl⋅40H2O
So Heat of dilution =−72.79−(−69.01)
=−3.78 mol kJ
Hence option (3) is incorrect.
For heat of formation reactant should be in elemental form hence option (4) is incorrect