[hexagon]

I have a question about the definition of the standard enthalpy change of neutralisation.
I am now revising for GCE A Level by Edexcel, and my textbook from 'A Pearson Company' states that 'the standard enthalpy change of neutralisation is the enthalpy change of a reaction where one mole of acid is just neutralised by an alkali in their standard states at 25^oC and in solution containing 1 mol dm^-3'
However I remember that from a book that I have previously read says that the standard enthalpy change of neutralisation should be the enthalpy change for producing one mole of water. And this for sure sounds more reasonable to me.

And now my question is: which should I follow in my exam?! (this would surely affects a lot for my calculations..)

Please anyone please answer my question!!!!!!!!!!!

[Borek]

One mole of monoprotic acid, or one mole of water produced. "One mole of an acid" is a lousy wording.