21.Heat of neutralisation of HCl and NaOH is -57.32 kJ per gram equivalent and that of acetic acid and NaOH is -55.23 kJ per gram equivalent. The heat of dissociation of acetic acid per gram equivalent should be

22.On burning hydrogen in an atmosphere of chlorine, 1.65 gm of HCl was obtained and 1 Kcal of heat was liberated. The heat of formation of HCl should be:

23.The apparatus used for measuring the heat changes is known as

24.The enthalpy of the elements in their standard states is taken as zero. So the enthalpy of formation of a compound may be

25.Which of the following will have maximum entropy?