as the stability of intermediate species increases there is increase the reactivity of this chemical reaction for example in the process of dehydration intermediate species is carbocation so reactivity of alcohol in the process of dehydration is 3>2>1.if we consider more example like C6H5SO3H is more acidic than C6H5COOH because intermediate C6H5SO3 anion is more stable than C6H5COO anion.in case of CHCl3 and CHF3 ,CHCl3 is more acidic because after releasing H+, CCl3 anion is more stable due to vacant orbital resonance which is not possible in intermediate CF3 anion.