I am confused with this solution question

Question

when solutions containing silver ions and chloride ions are mixed, silver chloride percipitates:

Ag ＋ Cl- → AgCl △H= -65.5 kJ

Calculate △H when 0.650 mol of AgCl dissolves in water

Answer 1

when AgCl dissolves in water you get the reverse equation of what you have above. So for 1mol you would have ΔH=65,5 whereas for 0,650mol about 42,6kJ