Why is the enthalpy of neutralization of strong acids more than that of weak acid?
enthalpy of neutralization of an acid by a base is defined as heat change when one gram equivalent of acid is neutralized by a base ,the reaction being carried out in dilute aqueous solution … enthalpy of neutralization of base by an acid is defined in a similar manner… for example when 1 gram equivalent of HCl is neutralized with NaOH 57.1 kj of heat is produced .. HCl (aq) + NaOH (aq)—-> NaCl (aq) + H2O (l)…ΔH = -57.1 kj/mole hence enthalpy of neutralization of HCl with NaOH is 57.1 kj enthalpy of neutralization of any strong acid (like HCl,HNO3,H2SO4) with a strong base (like LiOH,NaOH,KOH) or vice versa is always the same i.e. 57.1 kj…this is because strong acids ,strong bases and salt that they form are all completely ionized in dilute aqueous solutions …thus the reaction between any strong acid and strong base for example in the above case may be written as : NaOH (aq) + HCl(aq) —–> NaCl (aq) + H2O (l)… ΔH = -57.1 kj/mole they will dissociate as : Na(+) (aq) + OH
